def hash_to_range(element)
      hash = SipHash.digest(key, element)
      map_into_range(hash, f)
    end
def hash_to_range(element)
      hash = SipHash.digest(key, element)
      map_into_range(hash, f)
    end
Hash a data element to an integer in the range [0, F).
 @param [String] element with binary format.
 @return [Integer]