Javadoc
Sets the
StoredBlock that represents the top of the chain of greatest total work that has been
fully verified. It should generally be set after a batch of updates to the transaction unspent output set,
before a call to commitDatabaseBatchWrite.
If chainHead has a greater height than the non-verified chain head (ie that set with
BlockStore#setChainHead) the non-verified chain head should be set to the one set here.
In this way a class using a FullPrunedBlockStore only in full-verification mode can ignore the regular
BlockStore functions implemented as a part of a FullPrunedBlockStore.