code: public BlockInfo queryBlockByNumber(Peer peer, long blockNumber) throws InvalidArgumentException, ProposalException {
  
          return queryBlockByNumber(Collections.singleton(peer), blockNumber);
  
      }
docs: Query a peer in this channel for a Block by the blockNumber
  
  <STRONG>This method may not be thread safe if client context is changed!</STRONG>
  
  @param peer        the peer to send the request to
  @param blockNumber index of the Block in the chain
  @return the {@link BlockInfo} with the given blockNumber
  @throws InvalidArgumentException
  @throws ProposalException