 if necessary', () => {             const node = astNode.addNodeProperties({});             const descriptor = Object.getOwnPropertyDescriptor(node, 'enclosingScope');              expect(descriptor).toBeObject();             expect(descriptor.value).toBeUndefined();             expect(descriptor.enumerable).toBeFalse();             expect(descriptor.writable).toBeTrue();         });          it('should not overwrite an existing 