diff --git a/dagger/blockstream.nim b/dagger/blockstream.nim
deleted file mode 100644
index cb7601ce..00000000
--- a/dagger/blockstream.nim
+++ /dev/null
@@ -1,12 +0,0 @@
-## Nim-Dagger
-## Copyright (c) 2021 Status Research & Development GmbH
-## Licensed under either of
-##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
-##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
-## at your option.
-## This file may not be copied, modified, or distributed except according to
-## those terms.
-
-import ./blockstream/[blockstream, chunkedblockstream]
-
-export blockstream, chunkedblockstream
diff --git a/dagger/blocktype.nim b/dagger/blocktype.nim
index c4e65afd..e48bce61 100644
--- a/dagger/blocktype.nim
+++ b/dagger/blocktype.nim
@@ -35,6 +35,17 @@ func new*(
     data: @data)
 
 func new*(
+  T: type Block,
+  data: openArray[byte] = [],
+  version = CIDv1,
+  hcodec = multiCodec("sha2-256"),
+  codec = multiCodec("raw")): ?!T =
+  let hash =  MultiHash.digest($hcodec, data).get()
+  success Block(
+    cid: Cid.init(version, codec, hash).get(),
+    data: @data)
+
+proc new*(
   T: type Block,
   cid: Cid,
   data: openArray[byte] = [],
diff --git a/dagger/chunkedblockstream.nim b/dagger/chunkedblockstream.nim
deleted file mode 100644
index 49b6b6f5..00000000
--- a/dagger/chunkedblockstream.nim
+++ /dev/null
@@ -1,28 +0,0 @@
-## Nim-Dagger
-## Copyright (c) 2021 Status Research & Development GmbH
-## Licensed under either of
-##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
-##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
-## at your option.
-## This file may not be copied, modified, or distributed except according to
-## those terms.
-
-{.push raises: [Defect].}
-
-import pkg/questionable
-import pkg/questionable/results
-
-import ./blockstream
-import ./chunker
-
-type
-  ChunkedBlockStreamRef* = ref object of BlockStreamRef
-    chunker*: Chunker
-
-method nextBlock*(c: ChunkedBlockStreamRef): ?!Block =
-  let data: seq[byte] = c.chunker.getBytes()
-  if data.len > 0:
-    return success Block.new(data)
-
-proc new*(T: type ChunkedBlockStreamRef, chunker: Chunker): T =
-  T(chunker: chunker)
diff --git a/dagger/dataset.nim b/dagger/dataset.nim
index 7656bc06..48a23c03 100644
--- a/dagger/dataset.nim
+++ b/dagger/dataset.nim
@@ -26,10 +26,8 @@ proc hashBytes*(mh: MultiHash): seq[byte] =
   mh.data.buffer[mh.dpos..(mh.dpos + mh.size - 1)]
 
 proc hashBytes*(b: Block): seq[byte] =
-  without mh =? b.cid.mhash:
-    return
-
-  mh.hashBytes()
+  if mh =? b.cid.mhash:
+    mh.hashBytes()
 
 method nextBlock*(d: BlockSetRef): ?!Block =
   d.stream.nextBlock()
diff --git a/tests/dagger/dataset.nim b/tests/dagger/dataset.nim
new file mode 100644
index 00000000..ab01ef03
--- /dev/null
+++ b/tests/dagger/dataset.nim
@@ -0,0 +1,20 @@
+import std/sequtils
+
+import pkg/chronos
+import pkg/asynctest
+import pkg/stew/results
+import pkg/dagger/chunker
+import pkg/dagger/merkletree
+import pkg/stew/byteutils
+import pkg/dagger/p2p/rng
+import pkg/dagger/blocktype as bt
+
+suite "Data set":
+
+  test "Make from Blocks":
+    let
+      chunker = newRandomChunker(Rng.instance(), size = 256*3, chunkSize = 256)
+      blocks = chunker.mapIt( bt.Block.new(it) )
+
+    let merkle = MerkleTreeRef.fromBlocks(blocks)
+