public resolveKeybinding(keybinding: Keybinding): ResolvedKeybinding[] {
		let hashCode = keybinding.getHashCode();
		if (!this._cache.has(hashCode)) {
			let r = this._actual.resolveKeybinding(keybinding);
			this._cache.set(hashCode, r);
			return r;
		}
		return this._cache.get(hashCode);
	}

	public resolveKeybinding(keybinding: Keybinding): ResolvedKeybinding[] {
		const hashCode = keybinding.getHashCode();
		const resolved = this._cache.get(hashCode);
		if (!resolved) {
			const r = this._actual.resolveKeybinding(keybinding);
			this._cache.set(hashCode, r);
			return r;
		}
		return resolved;
	}

	test('getUserSettingsKeybindingRegex', () => {
		let regex = new RegExp(Keybinding.getUserSettingsKeybindingRegex());

		function testIsGood(userSettingsLabel:string, message:string = userSettingsLabel): void {
			let userSettings = '"' + userSettingsLabel.replace(/\\/g, '\\\\') + '"';
			let isGood = regex.test(userSettings);
			assert.ok(isGood, message);
		}

		// check that all key codes are covered by the regex
		let ignore: boolean[] = [];
		ignore[KeyCode.Shift] = true;
		ignore[KeyCode.Ctrl] = true;
		ignore[KeyCode.Alt] = true;
		ignore[KeyCode.Meta] = true;
		for (let keyCode = KeyCode.Unknown + 1; keyCode < KeyCode.MAX_VALUE; keyCode++) {
			if (ignore[keyCode]) {
				continue;
			}
			let userSettings = Keybinding.toUserSettingsLabel(keyCode);
			testIsGood(userSettings, keyCode + ' - ' + KeyCode[keyCode] + ' - ' + userSettings);
		}

		// one modifier
		testIsGood('ctrl+a');
		testIsGood('shift+a');
		testIsGood('alt+a');
		testIsGood('cmd+a');
		testIsGood('meta+a');
		testIsGood('win+a');

		// more modifiers
		testIsGood('ctrl+shift+a');
		testIsGood('shift+alt+a');
		testIsGood('ctrl+shift+alt+a');

		// chords
		testIsGood('ctrl+a ctrl+a');
	})

	public getElectronAcceleratorFor(keybinding: Keybinding): string {
		return keybinding._toElectronAccelerator();
	}

	public getAriaLabelFor(keybinding: Keybinding): string {
		return keybinding._toUSAriaLabel();
	}

	public getHTMLLabelFor(keybinding: Keybinding): IHTMLContentElement[] {
		return keybinding._toUSHTMLLabel();
	}