code: public static void printUnknownFieldValue(final int tag,
                                              final Object value,
                                              final Appendable output)
                                              throws IOException {
      printUnknownFieldValue(tag, value, new TextGenerator(output));
    }
docs: Outputs a textual representation of the value of an unknown field.
  
  @param tag the field's tag number
  @param value the value of the field
  @param output the output to which to append the formatted value
  @throws ClassCastException if the value is not appropriate for the
  given field descriptor
  @throws IOException if there is an exception writing to the output