docs: def snappy_encode(payload, xerial_compatible=False, xerial_blocksize=32 * 1024):
      """Encodes the given data with snappy if xerial_compatible is set then the
         stream is encoded in a fashion compatible with the xerial snappy library
  
         The block size (xerial_blocksize) controls how frequent the blocking
         occurs 32k is the default in the xerial library.
  
         The format winds up being
          +-------------+------------+--------------+------------+--------------+
          |   Header    | Block1 len | Block1 data  | Blockn len | Blockn data  |
          |-------------+------------+--------------+------------+--------------|
          |  16 bytes   |  BE int32  | snappy bytes |  BE int32  | snappy bytes |
          +-------------+------------+--------------+------------+--------------+
  
          It is important to not that the blocksize is the amount of uncompressed
          data presented to snappy at each block, whereas the blocklen is the
          number of bytes that will be present in the stream, that is the
          length will always be <= blocksize.
      """
  
      if not has_snappy():
          raise NotImplementedError("Snappy codec is not available")
  
      if xerial_compatible:
          def _chunker():
              for i in xrange(0, len(payload), xerial_blocksize):
                  yield payload[i:i + xerial_blocksize]
  
          out = BytesIO()
  
          header = b''.join([struct.pack('!' + fmt, dat) for fmt, dat
                             in zip(_XERIAL_V1_FORMAT, _XERIAL_V1_HEADER)])
  
          out.write(header)
          for chunk in _chunker():
              block = snappy.compress(chunk)
              block_size = len(block)
              out.write(struct.pack('!i', block_size))
              out.write(block)
  
          out.seek(0)
          return out.read()
  
      else:
          return snappy.compress(payload)