src/vs/base/common/keyCodes.ts/define
	function define(keyCode: KeyCode, uiLabel: string, usUserSettingsLabel: string = uiLabel, generalUserSettingsLabel: string = usUserSettingsLabel): void {
		uiMap.define(keyCode, uiLabel);
		userSettingsUSMap.define(keyCode, usUserSettingsLabel);
		userSettingsGeneralMap.define(keyCode, generalUserSettingsLabel);
	}