eventespresso / event-espresso-core

		//first let's order the menu groups by their internal menu order (note usort type hinting to ensure the incoming array is EE_Admin_Page_Menu_Map objects )

		usort( $this->_admin_menu_groups, array( $this, '_sort_menu_maps' ) );

		foreach ( $this->_admin_menu_groups as $group ) {

			if ( ! $group instanceof EE_Admin_Page_Menu_Group )

				throw new EE_Error( sprintf( __('Unable to continue sorting the menu groups array because there is an invalid value for the menu groups.  All values in this array are required to be a EE_Admin_Page_Menu_Group object.  Instead there was: %s', 'event_espresso'), print_r($group, TRUE) ) );

			$groups[$group->menu_slug] = $group;

		}

		return $groups;

	 * @throws \EE_Error

	 */

	protected static function _modify_datetime_object( DateTime $DateTime, $period = 'years', $value = 1, $operand = '+' ) {

		if ( ! $DateTime instanceof DateTime ) {

			throw new EE_Error(

				sprintf(

					__( 'Expected a PHP DateTime object, but instead received %1$s', 'event_espresso' ),

					print_r( $DateTime, true )

				)

			);

		}

		switch ( $period ) {

			case 'years' :

				$value = 'P' . $value . 'Y';

		}elseif( $primary_key_field instanceof EE_Primary_Key_String_Field && is_string($base_class_obj_or_id) ){

			//assume its a string representation of the object

			$model_object = $this->get_one_by_ID($base_class_obj_or_id);

		}else{

			throw new EE_Error(sprintf(__("'%s' is neither an object of type %s, nor an ID! Its full value is '%s'",'event_espresso'),$base_class_obj_or_id,$this->_get_class_name(),print_r($base_class_obj_or_id,true)));

		}

		if( $model_object->ID() == NULL && $ensure_is_in_db){

			$model_object->save();

		}

		}elseif(is_string($base_class_obj_or_id)){

			//assume its a string representation of the object

			$id = $base_class_obj_or_id;

		}else{

			throw new EE_Error(sprintf(__("'%s' is neither an object of type %s, nor an ID! Its full value is '%s'",'event_espresso'),$base_class_obj_or_id,$this->_get_class_name(),print_r($base_class_obj_or_id,true)));

		}

		return $id;

	}