src/vs/editor/contrib/wordPartOperations/wordPartOperations.ts/DeleteWordPartLeft/constructor
class DeleteWordPartLeft:	constructor() {
		super({
			whitespaceHeuristics: true,
			wordNavigationType: WordNavigationType.WordStart,
			id: 'deleteWordPartLeft',
			precondition: EditorContextKeys.writable,
			kbOpts: {
				kbExpr: EditorContextKeys.textInputFocus,
				primary: 0,
				mac: { primary: KeyMod.WinCtrl | KeyMod.Alt | KeyCode.Backspace },
				weight: KeybindingWeight.EditorContrib
			}
		});
	}