src/vs/workbench/api/common/apiCommands.ts/DiffAPICommand/execute
class DiffAPICommand:	public static execute(executor: ICommandsExecutor, left: URI, right: URI, label: string, options?: typeConverters.TextEditorOpenOptions): Promise<any> {
		return executor.executeCommand('_workbench.diff', [
			left, right,
			label,
		]);
	}