selectOnPoint(pointer) {
    let selected = false;
    if (this.options.selectable === true) {
      const obj = this.getNodeAt(pointer) || this.getEdgeAt(pointer);

      // unselect after getting the objects in order to restore width and height.
      this.unselectAll();

      if (obj !== undefined) {
        selected = this.selectObject(obj);
      }
      this.body.emitter.emit("_requestRedraw");
    }
    return selected;
  }
handles the selection part of the tap;
@param {{x: number, y: number}} pointer
@returns {boolean}