def delWidget(pageIndex, columnIndex, widgetIndex, retJson=True):
    """ Delete specific widget from current dashboard.

        @param pageIndex
        index of page the widget lies on( start from 0 )

        @param columnIndex
        index of column the widget lies on( start from 0 )

        @param widgetIndex
        index of the widget, count from top to bottom( start from 0 )

        @retJson
        format return value to json format or not( default True )

        @return
        a dict contains state of process, format like:
        {
            'success': True,
            'msg': 'Delete widget success.'
        }

        """
