loadFlexData(mPropertyBag) {
			return loadDataFromStorage({
				storage: this.oStorage,
				reference: mPropertyBag.reference
			}).then(function(aFlexObjects) {
				var mGroupedFlexObjects = StorageUtils.getGroupedFlexObjects(aFlexObjects);
				return StorageUtils.filterAndSortResponses(mGroupedFlexObjects);
			});
		}
Provides the flex data stored in the session or local storage;
Changes can be filtered by reference and layer.

@param {object} mPropertyBag properties needed by the connectors
@param {string} mPropertyBag.reference reference of the application
@returns {Promise<Object>} resolving with an object containing a data contained in the changes-bundle