code: public BlockInfo queryBlockByHash(Peer peer, byte[] blockHash) throws InvalidArgumentException, ProposalException {
          return queryBlockByHash(Collections.singleton(peer), blockHash);
      }
docs: Query a peer in this channel for a Block by the block hash.
  
  <STRONG>This method may not be thread safe if client context is changed!</STRONG>
  
  @param peer      the Peer to query.
  @param blockHash the hash of the Block in the chain.
  @return the {@link BlockInfo} with the given block Hash
  @throws InvalidArgumentException if the channel is shutdown or any of the arguments are not valid.
  @throws ProposalException        if an error occurred processing the query.