code: public OptionBuilder withLongForm( String longForm )
      {
          if (option.getLongForm() != null) throw new IllegalArgumentException( "Long form given twice" );
          option.setLongForm( longForm );
          return this;
      }
docs: <p>withLongForm.</p>
  
  @param longForm a {@link java.lang.String} object.
  @return a {@link com.greenpepper.util.cli.OptionBuilder} object.