public void TestCreateFromParentChain()
{
// create a chain
var fakeHeaders = new FakeHeaders();
var header0 = fakeHeaders.GenesisChained();
var header1 = fakeHeaders.NextChained();
var parentChain = new ChainBuilder(new[] { header0, header1 }).ToImmutable();
// create builder from chain
var chainBuilder = new ChainBuilder(parentChain);
// verify
CollectionAssert.AreEqual(new[] { header0, header1 }, chainBuilder.Blocks);
CollectionAssert.AreEquivalent(new Dictionary<UInt256, ChainedHeader> { { header0.Hash, header0 }, { header1.Hash, header1 } }, chainBuilder.BlocksByHash);
}