getGroupHeader(oGroup) {
			var sTitle = "{i18n>systemData}";

			if (oGroup.key === "custom") {
				sTitle = "{i18n>externalReferences}";
			}

			return new GroupHeaderListItem({
				title: sTitle
			});
		}
Factory for creating list group header objects for the metadata list.
@param {Object} oGroup - Group data passed from the lists model binding
@returns {sap.m.GroupHeaderListItem} New GroupHeaderListItem
@public