Commit Graph

223 Commits

Author SHA1 Message Date
tersec f5f939bd31
0.11.1 beacon chain spec update (#836)
* initial 0.11.1 spec commit; no test regressions and finalizes in eth2_network_simulation

* with BLS 0.10/0.11 available, stop skipping attester slashing, proposer slashing, and voluntary exist operations fixture tests

* switch param orders to group state.{fork, genesis_validators_root}; bump spec/datatypes spec version for network purposes

* mark attestation construction and broadcast and some minimal/mainnet constants as 0.11.1-compatible; remove phase 1 sharding constants from minimal which don't exist in that preset
2020-03-30 11:31:44 +00:00
tersec 53e4b0a26c
complete (except for get_domain(...)) 0.11.0 beacon chain spec update (#822)
* complete (except for get_domain(...)) 0.11.0 beacon chain spec update

* mark compute_start_slot_at_epoch(...), is_active_validator(...), compute_signing_root(...), and get_seed(...) as 0.11.0
2020-03-22 16:03:07 +00:00
Dustin Brody cae1c0fd1a address beacon_node TODO regarding missing proposer index; mark initiate_validator_exit(...), is_eligible_for_activation_queue(...), Attestation, DepositMessage, BeaconBlockBody, PendingAttestation, Eth1Data, and integer_squareroot(...) as 0.11.0 2020-03-17 12:06:56 +02:00
Dustin Brody ebcde664e5 mark decrease_balance(...), get_validator_churn_limit(...), network spec version, Checkpoint, compute_epoch_at_slot(...), get_active_validator_indices(...), and get_committee_count_at_slot(...) as 0.11.0 2020-03-17 12:06:56 +02:00
Dustin Brody 313109c743 align process_block(...) name with spec; fix beacon chain proposer index generation when some validators aren't active to fix the two regressing 0.11.0 block sanity tests 2020-03-17 12:06:56 +02:00
Dustin Brody 6068dd960b initial 0.11.0 spec version update 2020-03-17 12:06:56 +02:00
Dustin Brody 3d99c7b28e mark some spec functions .used. to avoid warnings; misc cleanups 2020-02-25 09:17:06 +00:00
Dustin Brody 3efbe36c30 additional 0.10.1 updates where already-implemented code is already done 2020-01-27 12:50:54 +00:00
Dustin Brody dab107fa1e more 0.10.1 updates 2020-01-27 12:50:54 +00:00
Mamy Ratsimbazafy 1ba2cebd85 v0.10.1 (test vectors + unchanged parts) (#696)
* update to 0.10.1

* SSZ Generic and nbench uses the v0.10.1 fixtures

* Tests + spec links: v0.10.0 -> v0.10.1

* Add v0.10.1 TODO in get_latest_attesting_balance (forkchoice)

* SSZ Bytes are now ByteList

* Remove nim-result submodules that was leftover/added by mistake in the branch
2020-01-27 10:56:32 +00:00
Jacek Sieka 7dc2434e0d
clean up attestation logging 2020-01-23 18:48:26 +01:00
Dustin Brody 50f633209c mark a couple dozen 0.9.2/0.9.4 spec locations as still consistent with 0.10.0; no functional changes 2020-01-22 13:03:45 +00:00
Mamy André-Ratsimbazafy b49003988a Add Epoch Processing to nbench 2020-01-15 10:03:56 +00:00
Dustin Brody 8eaebf7163 update to spec version 0.10.0 2020-01-14 18:17:16 +00:00
Dustin Brody 46de726e3d mark all compatible 0.9.3 functions and data structures as 0.9.4 2019-12-20 17:24:42 +00:00
Mamy Ratsimbazafy 106352aff3
Nbench - Flexible benchmarking of Nimbus internals (#641)
* nbench PoC

* Remove the yaml files from the example scenarios

* update README with current status

* Add an alternative implementation that uses defer

* Forgot to add the old proc body

* slots-processing

* allow benching state_transition failures

* Add Attestations processing (workaround confutils bug:
- https://github.com/status-im/nim-confutils/issues/10
- https://github.com/status-im/nim-confutils/issues/11
- https://github.com/status-im/nim-confutils/issues/12

* Add CLI command in the readme

* Filter report and add notes about CPU cycles

* Report averages

* Add debugecho style time/cycle print

* Report when we skip BLS and state root verification

* Update to 0.9.3

* Generalize scenario parsing

* Support all block processing scenarios

* parallel bench runner PoC

* gitBetter load issues reporting (the load issues were invalid signature and expected to fail)
2019-12-20 17:14:43 +01:00
Jacek Sieka 746659bdc6
bump stew, fix warnings (#655) 2019-12-20 14:25:33 +01:00
Dustin Brody 350a6c071a mark a couple compatible dozen 0.9.2 functions/data structures as 0.9.3 2019-12-18 16:13:39 +00:00
Dustin Brody 0328cd49bf mark several more functions and data structures as 0.9.3 2019-12-18 10:00:17 +00:00
Dustin Brody 1610981be6 mark several more spec-referencing code/data parts as 0.9.3 2019-12-17 16:51:46 +00:00
Dustin Brody 27bf8908a9 mark a couple dozen functions and data structures as 0.9.3; fix TRACE-level compiling; stop downloading 0.9.2 test vectors; update cosmetic/display spec versions in test suite 2019-12-17 16:51:46 +00:00
Dustin Brody 1494bcc262 replace links to Apache and MIT licenses with HTTPS versions (#592) 2019-11-25 16:30:02 +01:00
Dustin Brody 41fa377638 mark all non-changed 0.9.1 items as 0.9.2 (#576) 2019-11-22 09:29:04 +01:00
Dustin Brody c0f009908c
re-enable test_interop based on zcli with 0.9.1 specs and update initialize_beacon_state_from_eth1(...) to 0.9.1 (#569)
* re-enable test_interop based on zcli with 0.9.1 specs and update initialize_beacon_state_from_eth1(...) to 0.9.1

* switch many procs to funcs

* fix import os.nim instead; ospaths is deprecated [Deprecated] warnings
2019-11-21 09:15:10 +00:00
Dustin Brody 6f87c8fd89 verify that state_sim is justifying and finalizing; fix 3 more warnings; rename crosslink_committee_cache to beacon_committee_cache; fix O(n^2) usage of get_base_reward(...) 2019-11-18 17:35:58 +00:00
Dustin Brody 96dcb1cf95
Remove shard-relating code 2019-11-14 19:48:12 +01:00
Dustin Brody 3dcc00779a replace deprecated toSet(...) with toHashSet(...); replace implicit with more explicit default constructor for readability 2019-11-13 13:49:38 +00:00
Dustin Brody d5ce142511 fix network sim finalization; remove get_attestation_data_slot(...); remove 2 more get_crosslink_committee(...) calls 2019-11-12 14:49:26 +00:00
Dustin Brody d457dfee81 switch all but 4 remaining callers to get_crosslink_committee(...) to get_beacon_committee(...) 2019-11-11 11:46:03 +00:00
Dustin Brody 568fa1dcb9 mark functions, constants, and data structures unchanged by 0.9.1 as such 2019-11-11 10:25:57 +00:00
Dustin Brody e984b2c932 mark is_valid_merkle_branch(...), process_justification_and_finalization(...), and process_rewards_and_penalties(...) as 0.9.0; update check_attestation(...) to 0.9.0; add 11 working test fixtures, having updated SSZ fixture directory to 0.9.0 2019-11-08 13:23:08 +00:00
Dustin Brody 275fb22c00 flip targeted spec version and ssz test fixtures to 0.9.0; almost completely update BeaconState to 0.9.0; update minimal and mainnet preset constants to 0.9.0; update process_proposer_slashing(...), get_attestation_deltas(...), and get_matching_head_attestations(...) to 0.9.0; mark process_final_updates(...) as 0.9.0 2019-11-08 13:23:08 +00:00
Dustin Brody 61c2cf9415 rm get_compact_committees_root(...), Transfer, and references to 0.9-removed BeaconState.{active_index_roots,compact_committees_roots; temporarily disable genesis interop test pending 0.9 BeaconState 2019-11-08 13:23:08 +00:00
Dustin Brody 68654848cb update get_attesting_indices(...) to 0.9.0; remove Crosslink from AttestationData to update AttestationData to 0.9.0; rm get_winning_crosslink_and_attesting_indices(...) and get_crosslink_deltas(...) 2019-11-08 13:23:08 +00:00
Dustin Brody 63e621c27d
initial 0.9.0 spec sync (#509)
* rename compute_epoch_of_slot(...) to compute_epoch_at_slot(...)

* remove some unnecessary imports; remove some crosslink-related code and tests; complete renaming of compute_epoch_of_slot(...) to compute_epoch_at_slot(...)

* rm more transfer-related code and tests; rm more unnecessary strutils imports

* rm remaining unused imports

* remove useless get_empty_per_epoch_cache(...)/compute_start_slot_of_epoch(...) calls

* rename compute_start_slot_of_epoch(...) to compute_start_slot_at_epoch(...)

* rename ACTIVATION_EXIT_DELAY to MAX_SEED_LOOKAHEAD

* update domain types to 0.9.0

* mark AttesterSlashing, IndexedAttestation, AttestationDataAndCustodyBit, DepositData, BeaconBlockHeader, Fork, integer_squareroot(...), and process_voluntary_exit(...) as 0.9.0

* mark increase_balance(...), decrease_balance(...), get_block_root(...), CheckPoint, Deposit, PendingAttestation, HistoricalBatch, is_active_validator(...), and is_slashable_attestation_data(...) as 0.9.0

* mark compute_activation_exit_epoch(...), bls_verify(...), Validator, get_active_validator_indices(...), get_current_epoch(...), get_total_active_balance(...), and get_previous_epoch(...) as 0.9.0

* mark get_block_root_at_slot(...), ProposerSlashing, get_domain(...), VoluntaryExit, mainnet preset Gwei values, minimal preset max operations, process_block_header(...), and is_slashable_validator(...) as 0.9.0

* mark makeWithdrawalCredentials(...), get_validator_churn_limit(...), get_total_balance(...), is_valid_indexed_attestation(...), bls_aggregate_pubkeys(...), initial genesis value/constants, Attestation, get_randao_mix(...), mainnet preset max operations per block constants, minimal preset Gwei values and time parameters, process_eth1_data(...), get_shuffled_seq(...), compute_committee(...), and process_slots(...) as 0.9.0; partially update get_indexed_attestation(...) to 0.9.0 by removing crosslink refs and associated tests

* mark initiate_validator_exit(...), process_registry_updates(...), BeaconBlock, Eth1Data, compute_domain(...), process_randao(...), process_attester_slashing(...), get_base_reward(...), and process_slot(...) as 0.9.0
2019-10-30 19:41:19 +00:00
Jacek Sieka ee5d1c1467
minimize imports, specially for spec - cuts 2/3 of ncli build time (#500)
* minimize imports, specially for spec - cuts 2/3 of ncli build time
* ptr_arith->ptrops
2019-10-25 12:59:56 +02:00
Dustin Brody 700e7d921b
update to beacon chain phase 0 spec version 0.8.4; no substantive changes (#494) 2019-10-24 13:36:36 +00:00
Dustin Brody 4c0b2a9a32
implement beacon_pending_deposits, beacon_processed_deposits_total, beacon_previous_validators, and beacon_current_validators metrics (#478)
* implement additional beacon_current_validators and beacon_previous_validators metrics

* tentatively implement beacon_pending_deposits additional metric

* implement beacon_processed_deposits_total additional metric
2019-10-06 04:31:50 +00:00
Dustin Brody 1a62c122d8
Finish remaining required interop metrics (#477)
* implement beacon_finalized_root, beacon_current_justified_root, and beacon_previous_justified_root interop metrics
2019-10-03 18:16:25 +00:00
Dustin Brody 2122bb44c9
implement beacon_finalized_epoch, beacon_current_justified_epoch, and beacon_previous_justified_epoch (#476) 2019-10-03 10:36:31 +00:00
Jacek Sieka b8ddb776ca fix attestation selection when calculating rewards and penalties
Previously, the we'd use the first source attestation regardless if it
matches the filter or not leading to the wrong minimum being used
2019-10-02 12:17:02 +03:00
Zahary Karadjov c39d4f1817 Fix an overflow in the justification bits processing 2019-09-27 23:29:58 +03:00
Mamy Ratsimbazafy a7a1f78499
Fix TRACE chronicles_log_level (#451) 2019-09-23 17:00:10 +02:00
Mamy Ratsimbazafy b100ceef56
Add detailed finalization and justification debug logs (#449)
* Add detailed finalization and justification debug logs

* log was wrongfully reporting rule 123 instead of rule 12
2019-09-23 15:48:26 +02:00
Dustin Brody a4b4c89539 remove incorrect exit condition in get_attestation_details(...) (#416)
* remove incorrect exit condition in get_attestation_details(...)

* enable historical batch unit test, which now passes
2019-09-09 09:10:03 -04:00
Dustin Brody f882c92a42 fix network sim (#389)
* fix network sim

* mark BeaconState, state list/vector lengths, misc values, get_base_reward(...), verifyStateRoot(...), and process_slot(...) as 0.8.3; update minimal/mainnet config initial values to 0.8.3 by removing GENESIS_FORK_VERSION
2019-09-05 21:52:34 +02:00
zah 7ebf685fa3 Work-around for #373 (#385) 2019-09-05 10:27:26 +00:00
Mamy Ratsimbazafy ad240953ed Fix #378, int to bytes32, LATEST_RANDAO_MIXES, get_seed, get_crosslink_committee, get_compact_committee_root (#380) 2019-09-04 13:57:18 +00:00
Mamy Ratsimbazafy 297e9079d4 V0.8.3 tests part2 - BLS + Shuffling + State transition epoch (#372)
* Update BLS fixtures to 0.8.3

* Bump fixtures with shuffling with minimal preset

* Update shuffling tests

* parseTest generic over file format (Json or SSZ)

* Initial crosslink parsing commit for debugging Nim crash

* Workaround https://github.com/status-im/nim-beacon-chain/issues/369

* Crosslink test works for minimal - https://github.com/status-im/nim-beacon-chain/issues/369 is back on mainnet

* Use ref objects to workaround https://github.com/status-im/nim-beacon-chain/issues/369

* Generalize state transition epoch test to all epoch tests

* Fix slashing (potential uint64 overflow in previous spec)

* Add a state debugging macro to deeply inspect the wrong fields

* make reportDiff visible

* Improve the debug state macro for containers
2019-09-03 03:12:09 +00:00
Mamy Ratsimbazafy ca4f29caca v0.8.1 tests refactor (#326)
* Introduce new mocking proc to replace:
- makeFakeValidatorPrivKey
- hackPrivKey
- getNextBeaconProposerIndex
- addBlock
- makeBlock

* Add comments on datastructure unsynced with the spec

* Add merkle tree constructor and initial mocking for deposits (missing merkle proofs)

* [Mock] Implement sparse merkle tree and merkle proof builder

* [Mocking] Genesis deposits

* Add compact_committees_roots init + mock genesis state

* [Tests] Add first deposit test using the new mocking procedures

* [Tests -deposits] add at and over 32 ETH deposit tests

* [Tests - deposits] Add test for validator top-up

* [Tests -deposits] Mention the TODO to test for invalid conditions

* [Tests] Add stub to test "is_valid_genesis_state"

* [Merkle proofs] Implement round-trip checks

* Deactivate roundtrips test

* SSZ - use EF convention for hash_tree_root / hashTreeRoot

* [Tests - Attestation] Attestation mocking + initial test

* Add mocking + 3 new tests for valid attestations + mention future invalid attestation tests

* Add crosslinks test (1 failing to attestations in block being duplicated in state transition)

* Single attestation crosslink test - workaround https://github.com/status-im/nim-beacon-chain/issues/361

* Add test for failed crosslink penalty

* Rebase fixes + add refactored tests to test suite

* justif-finalization helpers first batch

* Add 234 finalization tests

* Fix justif test, Rule I 234 finalization does not happen with sufficient support.
(Also unittest check template does not fail properly in some cases)

* Add tests for all finalization rules

* Properly delete nim-byteutils following c91727e7e5 (diff-7c3613dba5171cb6027c67835dd3b9d4)

* use digest helper for deposit root
2019-08-28 12:07:00 +00:00
Dustin Brody 8665efbbd1 bump beacon chain versions to 0.8.3, which has no relevant changes in this regard (#358) 2019-08-26 11:09:47 +02:00
Dustin Brody c47e3903be rm some less-useful debug and tracing noise (#355) 2019-08-23 11:39:23 +02:00
Zahary Karadjov 912563648e
Fix the json build; Don't long the non-attesting indices in the testnets 2019-08-21 14:21:08 +03:00
Jacek Sieka 78f7a4a505 restore network sim finalization
* relax attestation validation when attestation is incoming but make it
more strict when adding to block
* share attestation validation logic between attestation pool and state
transition
* remove a bunch of redundant logging
* fix potential underflow in attestation delay checking
* fix committee used for attestation shard selection when attesting
* fix attestation data construction
2019-08-19 21:05:54 +03:00
Dustin Brody 3e587d4667
Justification/finalization amelioration using testnet1 shard count and epoch length (#331)
* working justification, 1 node, 64 validators

* closer to tn1 params: 256 validators

* more debugging output; switch to minimum test case

* working justification and finalization in local network simulation

* fix currently incorrect state transition/attestation test assumption
2019-08-14 08:56:32 +00:00
Dustin Brody 6704749eb0 mark unchanged 0.8.1 as 0.8.2 spec aspects (#336) 2019-08-09 14:08:00 +02:00
Zahary Karadjov 398ea55801
Implement the latest SSZ specification and integrate the official SSZ test suite 2019-08-05 03:18:48 +03:00
Zahary Karadjov 33dfc8b2d5
Fix the compilation when json logging is used 2019-07-16 13:40:24 +03:00
Dustin Brody b049dded88
summarize why previous epoch attestations can be recapped where they are 2019-07-16 11:16:04 +02:00
Dustin Brody f6fd089ae7
Add non-attesting-validators instrumentation in process_justification_and_finalization(...) (#323)
* update process_justifications_and_finalizations(...) to 0.8.1
2019-07-16 07:34:11 +00:00
Mamy Ratsimbazafy d1d5497233
v0.7.x-v0.8.1 state transition refactor part2 (#322)
* State sim compiles and run

* Works on libp2p testnet1

* Successfully update the state transition tests

* naive update of attestation pool (failing attstations can arrive in any order)

* Remove an official assert to allow attestation reordering
2019-07-15 23:10:40 +02:00
Dustin Brody 712038fe21
mark applicable 0.8.0-compliant functions and data structures as 0.8.1 and update a couple of other comments (#321) 2019-07-15 12:57:18 +00:00
Dustin Brody dfa062db7d 0.8.0, continued (#315)
* rename get_genesis_beacon_state(...) to initialize_beacon_state_from_eth1(...); remove unused vestiges get_temporary_block_header(...) and get_empty_block(...); partly align initialize_beacon_state_from_eth1(...) with 0.8.0 version; implement CompactCommittee object type; update process_final_updates(...) to 0.8.0

* mark get_shard_delta(...) as 0.8.0

* mark get_total_active_balance(...) and epoch transition helper functions as 0.8.0

* move FORK_CHOICE_BALANCE_INCREMENT, not in spec anymore, to sole user in fork_choice
2019-07-10 14:23:02 +02:00
Dustin Brody 0a2d09e7fe
Speed up process_crosslinks(...) and get_crosslink_deltas(...) by 10x - 15x in state_sim (#314)
* remove some low-hanging perf silliness from get_winning_crosslink_and_attesting_indices(...) and switch inner/outer loop nesting order to get 10-15x function speedup for 128 and 512 validator cases by avoiding accidentally quadratic behavior, while keeping function signature unchanged and allowing easy ongoing verification of correctness of optimization

* avoid memory allocation with an openarray rather than seq

* update get_crosslink_deltas(...) to 0.8.0

* move non-spec ValidatorSetDeltaFlags from datatypes.nim to sync_protocol; fix mainnet MIN_ATTESTATION_INCLUSION_DELAY preset; update get_attestation_deltas(...) to 0.8.0; for 512 validators, get 90x speedup for get_attestation_deltas(...) from 179s to 2s

* explain purpose of when false portions, so they can be removed once accomplished
2019-07-08 13:19:52 +00:00
Dustin Brody 68be98cafa
More 0.8.0 updates (#311)
* replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0

* update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0

* mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0

* rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...)

* convert remaining references to finalized_epoch to finalized_checkpoint.epoch

* update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0

* rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0

* update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0

* replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
2019-07-05 08:30:05 +00:00
Dustin Brody 8a5e5334d6 re-implement attestation checking in 0.8.0 form and rename relevant function from checkAttestation(...) to spec's process_attestation(...), though there's a slight difference in how they're factored; remove a couple of pointless type conversion warnings; rename validate_indexed_attestation(...) to is_valid_indexed_attestation(...); remove verify_bitfield(...) not in 0.8.0; update AttestationData to 0.8.0 by using Checkpoint data structure; rename MAX_CROSSLINK_EPOCHS to MAX_EPOCHS_PER_CROSSLINK 2019-07-03 10:41:42 +03:00
Dustin Brody d7905351eb update get_crosslink_committee(...) to 0.8.0 and fix https://github.com/status-im/nim-beacon-chain/issues/307 2019-07-02 19:52:39 +03:00
Dustin Brody fa39eb82c4 do most of 0.8.0 BeaconState updating, in particular field renamings, re-orderings, etc; rm now-unnecessary genesis block creation aspects, towards the near-stub version in current spec as mostfields are 0/default/etc values 2019-07-01 14:44:57 +03:00
Dustin Brody fb601bd5b8 rename BeaconState.validator_registry to BeaconState.validators 2019-07-01 14:44:57 +03:00
Dustin Brody dc98ffb09b update Validator to 0.8.0; update/refactor deposit contract/etc to constants category; mark process_rewards_and_penalties(...) as 0.8.0 2019-07-01 14:44:57 +03:00
Dustin Brody 607a7de5eb rename get_epoch_start_shard(...) to 0.8.0 get_start_shard(...) 2019-07-01 14:44:57 +03:00
Dustin Brody e4321dc4ed Initial frozen phase 0/v0.8.0 spec (#305)
* rename slot_to_epoch(...) to compute_epoch_of_slot(...)

* rename aggregation_bitfield/custody_bitfield fields to aggregation_bits/custody_bits; rename convert_to_indexed(...) to get_indexed_attestation(...); mark BeaconBlockHeader as 0.8.0; update minimal preset MIN_ATTESTATION_INCLUSION_DELAY/time parameters in general to 0.8

* fix beacon node compilation; it used slightly different capitalizations of slot_to_epoch/slotToEpoch

* mark integer_squareroot(...), Deposit, VoluntaryExit, and Transfer as 0.8.0; rename get_epoch_start_slot(...) to compute_start_slot_of_epoch(...)

* add new Domain alias for uint64; rename bls_domain(...) to compute_domain(...), MAX_INDICES_PER_ATTESTATION to MAX_VALIDATORS_PER_COMMITTEE, and SignatureDomain to DomainType; update get_domain(...) to 0.8.0

* update/mark initiate_validator_exit(...) and Crosslink as 0.8.0; rename BeaconState.latest_block_roots -> BeaconState.block_roots; mark HistoricalBatch as 0.8.0
2019-07-01 09:53:42 +02:00
Mamy Ratsimbazafy 214860cb88 Split state_transition (#301) 2019-06-28 13:44:44 +00:00