code: public UpdateReturnState update(final String datum) {
      if ((datum == null) || datum.isEmpty()) {
        return RejectedNullOrEmpty;
      }
      final byte[] data = datum.getBytes(UTF_8);
      return hashUpdate(hash(data, getSeed())[0] >>> 1);
    }
docs: Present this sketch with the given String.
  The string is converted to a byte array using UTF8 encoding.
  If the string is null or empty no update attempt is made and the method returns.
  
  <p>Note: this will not produce the same output hash values as the {@link #update(char[])}
  method and will generally be a little slower depending on the complexity of the UTF8 encoding.
  </p>
  
  @param datum The given String.
  @return
  <a href="{@docRoot}/resources/dictionary.html#updateReturnState">See Update Return State</a>