code: String stringAt(final int fromIndex, final int length,
              final Charset charset) {
          return new String(byteArray, fromIndex, length, charset);
      }
docs: Returns a string containing the characters in the specified part of the
  record.
  
  @param fromIndex index of the first byte of the string.
  @param length number of bytes to include in the string. If zero an empty
  string is returned.
  @param charset used for decoding the byte sequence into characters. It is
  callers responsibility to make sure that the selected byte
  range contains a valid byte sequence when working with
  multi-byte encodings such as UTF-8.
  @return the string represented by the bytes in the given range