hidableStacks (hidableStacks) {
        if (!arguments.length) {
            return this._hidableStacks;
        }
        this._hidableStacks = hidableStacks;
        return this;
    }
Allow named stacks to be hidden or shown by clicking on legend items.
This does not affect the behavior of hideStack or showStack.
@param {Boolean} [hidableStacks=false]
@returns {Boolean|StackMixin}