isNodeAt(x, y) {
        for (let i = 0; i < this.Input.length; i++) { if (this.Input[i].x === x && this.Input[i].y === y) return true; }
        for (let i = 0; i < this.Output.length; i++) { if (this.Output[i].x === x && this.Output[i].y === y) return true; }
        return false;
    }
@memberof layoutBuffer
Check if node is already at a position
Function is called while decreasing height to
check if it is possible without moving other node