code: def WriteHashes(self, arr):
          
          length = len(arr)
          self.WriteVarInt(length)
          for item in arr:
              ba = bytearray(binascii.unhexlify(item))
              ba.reverse()
              #            logger.info("WRITING HASH %s " % ba)
              self.WriteBytes(ba)
docs: Write an array of hashes to the stream.
  
          Args:
              arr (list): a list of 32 byte hashes.