parentBrushOn (brushOn) {
        if (!arguments.length) {
            return this._parentBrushOn;
        }
        this._parentBrushOn = brushOn;
        return this;
    }
This will be internally used by composite chart onto children. Please go not invoke directly.

@protected
@param {Boolean} [brushOn=false]
@returns {Boolean|CoordinateGridMixin}