function getInvisibleText(oControl) {
		if (!oControl._shortcutInvisibleText) {
			var oFunc = oControl.exit;
			oControl._shortcutInvisibleText = new InvisibleText();
			oControl._shortcutInvisibleText.toStatic();
			oControl.exit = function() {
				this._shortcutInvisibleText.destroy();
				oFunc.call(this);
			};
		}

		return oControl._shortcutInvisibleText;
	}
Gets or creates an InvisibleText for the control's shortcut accessiblity.

@param {sap.ui.core.Control} oControl A control that have shortcut assigned