minor

#424

src/main/java/de/metas/ui/web/window/model/DocumentQueryOrderBy.java

@@ -16,6 +16,8 @@
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
 
+import lombok.NonNull;
+
 /*
  * #%L
  * metasfresh-webui-api
@@ -29,11 +31,11 @@
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public
- * License along with this program.  If not, see
+ * License along with this program. If not, see
  * <http://www.gnu.org/licenses/gpl-2.0.html>.
  * #L%
  */
@@ -130,6 +132,7 @@ public boolean equals(final Object obj)
 		return false;
 	}
 
+	@NonNull
 	public String getFieldName()
 	{
 		return fieldName;
@@ -139,7 +142,7 @@ public boolean isAscending()
 	{
 		return ascending;
 	}
-	
+
 	public <T> Comparator<T> asComparator(final BiFunction<T, String, Object> fieldValueExtractor)
 	{
 		final Function<T, Object> keyExtractor = obj -> fieldValueExtractor.apply(obj, fieldName);