131   get checked(): boolean {  method in LitTreeNode
135   set checked(value) {  method in LitTreeNode
157       this.onChange(!this.data?.checked);
161   onChange(checked: boolean): void {
162     this.checked = checked;
163     this.data!.checked = checked;
165     this.dispatchEvent(new CustomEvent('change', { detail: checked }));
185       this.checkboxElement!.checked = true;
191     if (this.checked) {
196         if (this.checked) {
198             a.checked = true;
202 …this.nextElementSibling.querySelectorAll('lit-tree-node').forEach((a: any) => (a.checked = false));
211             (item: any) => item.checked
214             (item: any, index, array) => item.checked
217             element.parentElement.parentElement.previousElementSibling.checked = true;
323         this.checkboxElement.checked = this.hasAttribute('checked');