code: public static long createHash(byte[] data) {
          long h = 0;
          byte[] res;
  
          synchronized (digestFunction) {
              res = digestFunction.digest(data);
          }
  
          for (int i = 0; i < 4; i++) {
              h <<= 8;
              h |= ((int) res[i]) & 0xFF;
          }
          return h;
      }
docs: Generates a digest based on the contents of an array of bytes.
  
  @param data specifies input data.
  @return digest as long.