changeControlSignalSize(size) {
        if (size === undefined || size < 1 || size > 32) return;
        if (this.controlSignalSize === size) return;
        const obj = new Multiplexer(
            this.x,
            this.y,
            this.scope,
            this.direction,
            this.bitWidth,
            size
        );
        this.cleanDelete();
        simulationArea.lastSelected = obj;
        return obj;
    }
@memberof Multiplexer
function to change control signal of the element