Date minDate = null;
for (TimelineDatasourceProperties ds : datasources) {
Indexed cont = ds.getDatasource();
Object timestampPropertyId = getGraphTimestampPropertyId(cont);
if (timestampPropertyId != null && cont.size() > 0) {
Item item = cont.getItem(cont.firstItemId());
if (item != null
&& item.getItemPropertyIds().contains(
timestampPropertyId)) {
Property<?> property = item
.getItemProperty(timestampPropertyId);