code: def hash_from_stream(n, hash_stream):
      
      _to_int64 = to_int64
      x = 0x345678
      multiplied = _to_int64(1000003)
      for n in range(n - 1, -1, -1):
          h = next(hash_stream)
          x = _to_int64((x ^ h) * multiplied)
          multiplied += _to_int64(82520 + _to_int64(2 * n))
          multiplied = _to_int64(multiplied)
  
      x += 97531
      x = _to_int64(x)
      if x == -1:
          return -2
  
      return x
docs: Not standard hashing algorithm!
      Install NumPy for better hashing service.
      >>> from Redy.Tools._py_hash import hash_from_stream
      >>> s = iter((1, 2, 3))
      >>> assert hash_from_stream(3, map(hash, s)) == hash((1, 2, 3))