function _isGroupAppoitment(oRow, oAppointment) {
		var oGroupAppointments = oRow.getAggregation("groupAppointments", []);

		var i;
		for (i = 0; i < oGroupAppointments.length; ++i) {
			if (oAppointment === oGroupAppointments[i]) {
				return true;
			}
		}
		return false;
	}
Removes or adds the given appointment id from this.aSelectedAppointments
@param {sap.ui.unified.CalendarAppointment} oAppointment the appointment whose id should be added or remove=
@private