code: public OptionBuilder wantsArgument( String value )
      {
          if (option.wantsArg()) throw new IllegalArgumentException( "Argument pattern given twice" );
          option.setArg( value );
          return this;
      }
docs: <p>wantsArgument.</p>
  
  @param value a {@link java.lang.String} object.
  @return a {@link com.greenpepper.util.cli.OptionBuilder} object.