src/vs/workbench/contrib/mergeEditor/browser/model/mergeEditorModel.ts/MergeEditorModel/undo
class MergeEditorModel:	public setInputHandled(baseRange: ModifiedBaseRange, inputNumber: InputNumber, handled: boolean, tx: ITransaction): void {
		const state = this.modifiedBaseRangeResultStates.get().get(baseRange)!;
		if (state.handled.get() === handled) {
			return;
		}

		const dataRef = new WeakRef(ModifiedBaseRangeData);
		const modelRef = new WeakRef(this);

		this.undoRedoService.pushElement({
			type: UndoRedoElementType.Resource,
			resource: this.resultTextModel.uri,
			code: 'setInputHandled',
			label: localize('setInputHandled', "Set Input Handled"),
			redo() {
				const model = modelRef.deref();
				const data = dataRef.deref();
				if (model && !model.isDisposed() && data) {
					transaction(tx => {
						if (inputNumber === 1) {
							state.handledInput1.set(handled, tx);
						} else {
							state.handledInput2.set(handled, tx);
						}
					});
				}
			},
			undo() {
				const model = modelRef.deref();
				const data = dataRef.deref();
				if (model && !model.isDisposed() && data) {
					transaction(tx => {
						if (inputNumber === 1) {
							state.handledInput1.set(!handled, tx);
						} else {
							state.handledInput2.set(!handled, tx);
						}
					});
				}
			},
		});

		if (inputNumber === 1) {
			state.handledInput1.set(handled, tx);
		} else {
			state.handledInput2.set(handled, tx);
		}
	}