onTap(event) {
    const pointer = this.getPointer(event.center);
    const multiselect =
      this.selectionHandler.options.multiselect &&
      (event.changedPointers[0].ctrlKey || event.changedPointers[0].metaKey);

    this.checkSelectionChanges(pointer, multiselect);

    this.selectionHandler.commitAndEmit(pointer, event);
    this.selectionHandler.generateClickEvent("click", event, pointer);
  }
handle tap/click event: select/unselect a node
@param {Event} event
@private