code: def create_chunker(self, chunk_size):
          
          rolling_hash = _rabinkarprh.RabinKarpHash(self.window_size, self._seed)
          rolling_hash.set_threshold(1.0 / chunk_size)
          return RabinKarpCDC._Chunker(rolling_hash)
docs: Create a chunker performing content-defined chunking (CDC) using Rabin Karp's rolling hash scheme with a
          specific, expected chunk size.
  
          Args:
              chunk_size (int): (Expected) target chunk size.
  
          Returns:
              BaseChunker: A chunker object.