code: public BlockInfo queryBlockByNumber(long blockNumber) throws InvalidArgumentException, ProposalException {
          return queryBlockByNumber(getShuffledPeers(EnumSet.of(PeerRole.LEDGER_QUERY)), blockNumber);
      }
docs: query this channel for a Block by the blockNumber.
  The request is retried on all peers till successful
  
  <STRONG>This method may not be thread safe if client context is changed!</STRONG>
  
  @param blockNumber index of the Block in the chain
  @return the {@link BlockInfo} with the given blockNumber
  @throws InvalidArgumentException
  @throws ProposalException