code: def value(value_info, label=None, desc=None):
      
      _annotate("value", value_info, label=label, desc=desc)
docs: Annotate the value information of the action being defined.
      @param value_info: the value parameter information.
      @type value_info: value.IValueInfo
      @param label: the parameter label or None.
      @type label: str or unicode or None
      @param desc: the parameter description or None.
      @type desc: str or unicode or None