function convertLegacyFilter(oFilter) {
		// check if sap.ui.model.odata.Filter is used. If yes, convert it to sap.ui.model.Filter
		if (oFilter && typeof oFilter.convert === "function") {
			oFilter = oFilter.convert();
		}
		return oFilter;
	}
Create URL parameters for sorting
@param {array} aSorters an array of sap.ui.model.Sorter
@return {string} the URL encoded sorter parameters
@private