const { ethers } = require("hardhat") const { hexlify, randomBytes } = ethers.utils const { expect } = require("chai") const { exampleRequest } = require("./examples") const { hours, minutes } = require("./time") const { requestId, slotId, askToArray } = require("./ids") const { waitUntilCancelled, waitUntilStarted, waitUntilFinished, waitUntilFailed, RequestState, } = require("./marketplace") const { price, pricePerSlot } = require("./price") const { snapshot, revert, ensureMinimumBlockHeight, advanceTime, currentTime, } = require("./evm") describe("Marketplace", function () { const collateral = 100 const proofPeriod = 30 * 60 const proofTimeout = 5 const proofDowntime = 64 const proof = hexlify(randomBytes(42)) let marketplace let token let client, host, host1, host2, host3 let request let slot beforeEach(async function () { await snapshot() await ensureMinimumBlockHeight(256) ;[client, host1, host2, host3] = await ethers.getSigners() host = host1 const TestToken = await ethers.getContractFactory("TestToken") token = await TestToken.deploy() for (account of [client, host1, host2, host3]) { await token.mint(account.address, 1_000_000_000) } const Marketplace = await ethers.getContractFactory("TestMarketplace") marketplace = await Marketplace.deploy( token.address, collateral, proofPeriod, proofTimeout, proofDowntime ) request = await exampleRequest() request.client = client.address slot = { request: requestId(request), index: request.ask.slots / 2, } }) afterEach(async function () { await revert() }) function switchAccount(account) { token = token.connect(account) marketplace = marketplace.connect(account) } describe("requesting storage", function () { beforeEach(function () { switchAccount(client) }) it("emits event when storage is requested", async function () { await token.approve(marketplace.address, price(request)) await expect(marketplace.requestStorage(request)) .to.emit(marketplace, "StorageRequested") .withArgs(requestId(request), askToArray(request.ask)) }) it("rejects request with invalid client address", async function () { let invalid = { ...request, client: host.address } await token.approve(marketplace.address, price(invalid)) await expect(marketplace.requestStorage(invalid)).to.be.revertedWith( "Invalid client address" ) }) it("rejects request with insufficient payment", async function () { let insufficient = price(request) - 1 await token.approve(marketplace.address, insufficient) await expect(marketplace.requestStorage(request)).to.be.revertedWith( "ERC20: insufficient allowance" ) }) it("rejects resubmission of request", async function () { await token.approve(marketplace.address, price(request) * 2) await marketplace.requestStorage(request) await expect(marketplace.requestStorage(request)).to.be.revertedWith( "Request already exists" ) }) }) describe("filling a slot", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("emits event when slot is filled", async function () { await expect(marketplace.fillSlot(slot.request, slot.index, proof)) .to.emit(marketplace, "SlotFilled") .withArgs(slot.request, slot.index, slotId(slot)) }) it("locks collateral of host", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect(marketplace.withdraw()).to.be.revertedWith("Account locked") }) it("starts requiring storage proofs", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) expect(await marketplace.proofEnd(slotId(slot))).to.be.gt(0) }) it("is rejected when proof is incorrect", async function () { let invalid = hexlify([]) await expect( marketplace.fillSlot(slot.request, slot.index, invalid) ).to.be.revertedWith("Invalid proof") }) it("is rejected when collateral is insufficient", async function () { let insufficient = collateral - 1 await marketplace.withdraw() await token.approve(marketplace.address, insufficient) await marketplace.deposit(insufficient) await expect( marketplace.fillSlot(slot.request, slot.index, proof) ).to.be.revertedWith("Insufficient collateral") }) it("is rejected when slot already filled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect( marketplace.fillSlot(slot.request, slot.index, proof) ).to.be.revertedWith("Slot already filled") }) it("is rejected when request is unknown", async function () { let unknown = await exampleRequest() await expect( marketplace.fillSlot(requestId(unknown), 0, proof) ).to.be.revertedWith("Unknown request") }) it("is rejected when request is cancelled", async function () { switchAccount(client) let expired = { ...request, expiry: (await currentTime()) - hours(1) } await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(expired) switchAccount(host) await expect( marketplace.fillSlot(requestId(expired), slot.index, proof) ).to.be.revertedWith("Request not accepting proofs") }) it("is rejected when request is finished", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await expect( marketplace.fillSlot(slot.request, slot.index, proof) ).to.be.revertedWith("Request not accepting proofs") }) it("is rejected when request is failed", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFailed(marketplace, request, slot) await expect( marketplace.fillSlot(slot.request, slot.index, proof) ).to.be.revertedWith("Request not accepting proofs") }) it("is rejected when slot index not in range", async function () { const invalid = request.ask.slots await expect( marketplace.fillSlot(slot.request, invalid, proof) ).to.be.revertedWith("Invalid slot") }) it("fails when all slots are already filled", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i <= lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } await expect( marketplace.fillSlot(slot.request, lastSlot, proof) ).to.be.revertedWith("Slot already filled") }) }) describe("proof end", function () { var requestTime beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) requestTime = await currentTime() switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("shares proof end time for all slots in request", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i < lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } advanceTime(minutes(10)) await marketplace.fillSlot(slot.request, lastSlot, proof) let slot0 = { ...slot, index: 0 } let end = await marketplace.proofEnd(slotId(slot0)) for (let i = 1; i <= lastSlot; i++) { let sloti = { ...slot, index: i } await expect((await marketplace.proofEnd(slotId(sloti))) === end) } }) it("sets the proof end time to now + duration", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect( (await marketplace.proofEnd(slotId(slot))).toNumber() ).to.be.closeTo(requestTime + request.ask.duration, 1) }) it("sets proof end time to the past once failed", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFailed(marketplace, request, slot) let slot0 = { ...slot, index: request.ask.maxSlotLoss + 1 } const now = await currentTime() await expect(await marketplace.proofEnd(slotId(slot0))).to.be.eq(now - 1) }) it("sets proof end time to the past once cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await waitUntilCancelled(request) const now = await currentTime() await expect(await marketplace.proofEnd(slotId(slot))).to.be.eq(now - 1) }) it("checks that proof end time is in the past once finished", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) const now = await currentTime() // in the process of calling currentTime and proofEnd, // block.timestamp has advanced by 1, so the expected proof end time will // be block.timestamp - 1. await expect(await marketplace.proofEnd(slotId(slot))).to.be.eq(now - 1) }) }) describe("request end", function () { var requestTime beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) requestTime = await currentTime() switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("shares request end time for all slots in request", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i < lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } advanceTime(minutes(10)) await marketplace.fillSlot(slot.request, lastSlot, proof) let slot0 = { ...slot, index: 0 } let end = await marketplace.requestEnd(requestId(request)) for (let i = 1; i <= lastSlot; i++) { let sloti = { ...slot, index: i } await expect((await marketplace.proofEnd(slotId(sloti))) === end) } }) it("sets the request end time to now + duration", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect( (await marketplace.requestEnd(requestId(request))).toNumber() ).to.be.closeTo(requestTime + request.ask.duration, 1) }) it("sets request end time to the past once failed", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFailed(marketplace, request, slot) let slot0 = { ...slot, index: request.ask.maxSlotLoss + 1 } const now = await currentTime() await expect(await marketplace.requestEnd(requestId(request))).to.be.eq( now - 1 ) }) it("sets request end time to the past once cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await waitUntilCancelled(request) const now = await currentTime() await expect(await marketplace.requestEnd(requestId(request))).to.be.eq( now - 1 ) }) it("checks that request end time is in the past once finished", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) const now = await currentTime() // in the process of calling currentTime and proofEnd, // block.timestamp has advanced by 1, so the expected proof end time will // be block.timestamp - 1. await expect(await marketplace.requestEnd(requestId(request))).to.be.eq( now - 1 ) }) }) describe("freeing a slot", function () { var id beforeEach(async function () { slot.index = 0 id = slotId(slot) switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("fails to free slot when slot not filled", async function () { slot.index = 5 let nonExistentId = slotId(slot) await expect(marketplace.freeSlot(nonExistentId)).to.be.revertedWith( "Slot empty" ) }) it("fails to free slot when cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await waitUntilCancelled(request) await expect(marketplace.freeSlot(slotId(slot))).to.be.revertedWith( "Slot not accepting proofs" ) }) it("fails to free slot when finished", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await expect(marketplace.freeSlot(slotId(slot))).to.be.revertedWith( "Slot not accepting proofs" ) }) it("successfully frees slot", async function () { await waitUntilStarted(marketplace, request, proof) await expect(marketplace.freeSlot(id)).not.to.be.reverted }) it("emits event once slot is freed", async function () { await waitUntilStarted(marketplace, request, proof) await expect(await marketplace.freeSlot(id)) .to.emit(marketplace, "SlotFreed") .withArgs(slot.request, id) }) it("cannot get slot once freed", async function () { await waitUntilStarted(marketplace, request, proof) await marketplace.freeSlot(id) await expect(marketplace.slot(id)).to.be.revertedWith("Slot empty") }) }) describe("paying out a slot", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("pays the host", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) const startBalance = await token.balanceOf(host.address) await marketplace.payoutSlot(slot.request, slot.index) const endBalance = await token.balanceOf(host.address) expect(endBalance - startBalance).to.equal(pricePerSlot(request)) }) it("is only allowed when the contract has ended", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect( marketplace.payoutSlot(slot.request, slot.index) ).to.be.revertedWith("Contract not ended") }) it("can only be done once", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) await expect( marketplace.payoutSlot(slot.request, slot.index) ).to.be.revertedWith("Already paid") }) it("cannot be filled again", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) await expect(marketplace.fillSlot(slot.request, slot.index, proof)).to.be .reverted }) }) describe("fulfilling a request", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("emits event when all slots are filled", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i < lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } await expect(marketplace.fillSlot(slot.request, lastSlot, proof)) .to.emit(marketplace, "RequestFulfilled") .withArgs(requestId(request)) }) it("sets state when all slots are filled", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i <= lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } await expect(await marketplace.state(slot.request)).to.equal( RequestState.Started ) }) it("fails when all slots are already filled", async function () { const lastSlot = request.ask.slots - 1 for (let i = 0; i <= lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } await expect( marketplace.fillSlot(slot.request, lastSlot, proof) ).to.be.revertedWith("Slot already filled") }) }) describe("withdrawing funds", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("rejects withdraw when request not yet timed out", async function () { switchAccount(client) await expect(marketplace.withdrawFunds(slot.request)).to.be.revertedWith( "Request not yet timed out" ) }) it("rejects withdraw when wrong account used", async function () { await waitUntilCancelled(request) await expect(marketplace.withdrawFunds(slot.request)).to.be.revertedWith( "Invalid client address" ) }) it("rejects withdraw when in wrong state", async function () { // fill all slots, should change state to RequestState.Started const lastSlot = request.ask.slots - 1 for (let i = 0; i <= lastSlot; i++) { await marketplace.fillSlot(slot.request, i, proof) } await waitUntilCancelled(request) switchAccount(client) await expect(marketplace.withdrawFunds(slot.request)).to.be.revertedWith( "Invalid state" ) }) it("emits event once request is cancelled", async function () { await waitUntilCancelled(request) switchAccount(client) await expect(marketplace.withdrawFunds(slot.request)) .to.emit(marketplace, "RequestCancelled") .withArgs(requestId(request)) }) it("withdraws to the client", async function () { await waitUntilCancelled(request) switchAccount(client) const startBalance = await token.balanceOf(client.address) await marketplace.withdrawFunds(slot.request) const endBalance = await token.balanceOf(client.address) expect(endBalance - startBalance).to.equal(price(request)) }) }) describe("contract state", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("changes state to Cancelled when client withdraws funds", async function () { await expect(await marketplace.state(slot.request)).to.equal( RequestState.New ) }) it("state is Cancelled when client withdraws funds", async function () { await waitUntilCancelled(request) switchAccount(client) await marketplace.withdrawFunds(slot.request) await expect(await marketplace.state(slot.request)).to.equal( RequestState.Cancelled ) }) it("changes state to Started once all slots are filled", async function () { await waitUntilStarted(marketplace, request, proof) await expect(await marketplace.state(slot.request)).to.equal( RequestState.Started ) }) it("state is Failed once too many slots are freed", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFailed(marketplace, request, slot) await expect(await marketplace.state(slot.request)).to.equal( RequestState.Failed ) }) it("state is Finished once slot is paid out", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) await expect(await marketplace.state(slot.request)).to.equal( RequestState.Finished ) }) it("does not change state to Failed if too many slots freed but contract not started", async function () { for (let i = 0; i <= request.ask.maxSlotLoss; i++) { await marketplace.fillSlot(slot.request, i, proof) } for (let i = 0; i <= request.ask.maxSlotLoss; i++) { slot.index = i let id = slotId(slot) await marketplace.freeSlot(id) } await expect(await marketplace.state(slot.request)).to.equal( RequestState.New ) }) it("changes state to Cancelled once request is cancelled", async function () { await waitUntilCancelled(request) await expect(await marketplace.state(slot.request)).to.equal( RequestState.Cancelled ) }) it("changes isCancelled to true once request is cancelled", async function () { await expect(await marketplace.isCancelled(slot.request)).to.be.false await waitUntilCancelled(request) await expect(await marketplace.isCancelled(slot.request)).to.be.true }) it("rejects isSlotCancelled when slot is empty", async function () { await expect( marketplace.isSlotCancelled(slotId(slot)) ).to.be.revertedWith("Slot empty") }) it("changes isSlotCancelled to true once request is cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect(await marketplace.isSlotCancelled(slotId(slot))).to.be.false await waitUntilCancelled(request) await expect(await marketplace.isSlotCancelled(slotId(slot))).to.be.true }) it("changes proofEnd to the past when request is cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await expect(await marketplace.proofEnd(slotId(slot))).to.be.gt( await currentTime() ) await waitUntilCancelled(request) await expect(await marketplace.proofEnd(slotId(slot))).to.be.lt( await currentTime() ) }) }) describe("modifiers", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) describe("accepting proofs", function () { it("fails when request Cancelled (isCancelled is true)", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await waitUntilCancelled(request) await expect( marketplace.testAcceptsProofs(slotId(slot)) ).to.be.revertedWith("Slot not accepting proofs") }) it("fails when request Cancelled (state set to Cancelled)", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) await waitUntilCancelled(request) switchAccount(client) await marketplace.withdrawFunds(slot.request) await expect( marketplace.testAcceptsProofs(slotId(slot)) ).to.be.revertedWith("Slot not accepting proofs") }) it("fails when request Finished (isFinished is true)", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await expect( marketplace.testAcceptsProofs(slotId(slot)) ).to.be.revertedWith("Slot not accepting proofs") }) it("fails when request Finished (state set to Finished)", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) await expect( marketplace.testAcceptsProofs(slotId(slot)) ).to.be.revertedWith("Slot not accepting proofs") }) it("fails when request Failed", async function () { await waitUntilStarted(marketplace, request, proof) for (let i = 0; i <= request.ask.maxSlotLoss; i++) { slot.index = i let id = slotId(slot) await marketplace.freeSlot(id) } await expect( marketplace.testAcceptsProofs(slotId(slot)) ).to.be.revertedWith("Slot empty") }) }) }) describe("list of active requests", function () { beforeEach(async function () { switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) switchAccount(client) await token.approve(marketplace.address, price(request)) }) it("adds request to list when requesting storage", async function () { await marketplace.requestStorage(request) expect(await marketplace.myRequests()).to.deep.equal([requestId(request)]) }) it("keeps request in list when cancelled", async function () { await marketplace.requestStorage(request) await waitUntilCancelled(request) expect(await marketplace.myRequests()).to.deep.equal([requestId(request)]) }) it("removes request from list when funds are withdrawn", async function () { await marketplace.requestStorage(request) await waitUntilCancelled(request) await marketplace.withdrawFunds(requestId(request)) expect(await marketplace.myRequests()).to.deep.equal([]) }) it("keeps request in list when request fails", async function () { await marketplace.requestStorage(request) switchAccount(host) await waitUntilStarted(marketplace, request, proof) await waitUntilFailed(marketplace, request, slot) switchAccount(client) expect(await marketplace.myRequests()).to.deep.equal([requestId(request)]) }) it("removes request from list when request finishes", async function () { await marketplace.requestStorage(request) switchAccount(host) await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) switchAccount(client) expect(await marketplace.myRequests()).to.deep.equal([]) }) }) describe("list of active slots", function () { beforeEach(async function () { switchAccount(client) await token.approve(marketplace.address, price(request)) await marketplace.requestStorage(request) switchAccount(host) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) }) it("adds slot to list when filling slot", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) let slot1 = { ...slot, index: slot.index + 1 } await marketplace.fillSlot(slot.request, slot1.index, proof) expect(await marketplace.mySlots()).to.have.members([ slotId(slot), slotId(slot1), ]) }) it("removes slot from list when slot is freed", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) let slot1 = { ...slot, index: slot.index + 1 } await marketplace.fillSlot(slot.request, slot1.index, proof) await marketplace.freeSlot(slotId(slot)) expect(await marketplace.mySlots()).to.have.members([slotId(slot1)]) }) it("keeps slots when cancelled", async function () { await marketplace.fillSlot(slot.request, slot.index, proof) let slot1 = { ...slot, index: slot.index + 1 } await marketplace.fillSlot(slot.request, slot1.index, proof) await waitUntilCancelled(request) expect(await marketplace.mySlots()).to.have.members([ slotId(slot), slotId(slot1), ]) }) it("removes active slots for all hosts in a request when it fails", async function () { let halfOfSlots = request.ask.slots / 2 // fill half the slots with host1 for (let i = 0; i < Math.floor(halfOfSlots); i++) { await marketplace.fillSlot(requestId(request), i, proof) } // fill other half of slots with host2 switchAccount(host2) await token.approve(marketplace.address, collateral) await marketplace.deposit(collateral) for (let i = Math.floor(halfOfSlots); i < request.ask.slots; i++) { await marketplace.fillSlot(requestId(request), i, proof) } await waitUntilFailed(marketplace, request, slot) expect(await marketplace.mySlots()).to.have.members([]) switchAccount(host) expect(await marketplace.mySlots()).to.have.members([]) }) it("doesn't remove active slots for hosts in request that didn't fail", async function () { // start first request await waitUntilStarted(marketplace, request, proof) // start a second request let request2 = await exampleRequest() request2.client = client.address switchAccount(client) await token.approve(marketplace.address, price(request2)) await marketplace.requestStorage(request2) switchAccount(host) await waitUntilStarted(marketplace, request2, proof) // wait until first request fails await waitUntilFailed(marketplace, request, slot) // check that our active slots only contains slotIds from second request let expected = [] let expectedSlot = { ...slot, index: 0, request: requestId(request2) } for (let i = 0; i < request2.ask.slots; i++) { expectedSlot.index = i let id = slotId(expectedSlot) expected.push(id) } expect(await marketplace.mySlots()).to.have.members(expected) }) it("removes slot from list when slot is paid out", async function () { await waitUntilStarted(marketplace, request, proof) await waitUntilFinished(marketplace, requestId(request)) await marketplace.payoutSlot(slot.request, slot.index) expect(await marketplace.mySlots()).to.not.contain(slotId(slot)) }) }) })