Index: /trunk/src/org/openstreetmap/josm/actions/relation/AbstractRelationAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/relation/AbstractRelationAction.java	(revision 11589)
+++ /trunk/src/org/openstreetmap/josm/actions/relation/AbstractRelationAction.java	(revision 11590)
@@ -25,7 +25,5 @@
             return Collections.<Relation>emptySet();
         } else {
-            // Diamond operator does not work with Java 9 here
-            return new SubclassFilteredCollection<OsmPrimitive, Relation>(
-                    primitives, Relation.class::isInstance);
+            return new SubclassFilteredCollection<>(primitives, Relation.class::isInstance);
         }
     }
Index: /trunk/src/org/openstreetmap/josm/command/DeleteCommand.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/command/DeleteCommand.java	(revision 11589)
+++ /trunk/src/org/openstreetmap/josm/command/DeleteCommand.java	(revision 11590)
@@ -403,7 +403,5 @@
             return null;
 
-        // Diamond operator does not work with Java 9 here
-        @SuppressWarnings("unused")
-        Set<OsmPrimitive> primitivesToDelete = new HashSet<OsmPrimitive>(selection);
+        Set<OsmPrimitive> primitivesToDelete = new HashSet<>(selection);
 
         Collection<Relation> relationsToDelete = Utils.filteredCollection(primitivesToDelete, Relation.class);
Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java	(revision 11589)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java	(revision 11590)
@@ -310,7 +310,5 @@
     public Command fixError(TestError testError) {
         if (!isFixable(testError)) return null;
-        // Diamond operator does not work with Java 9 here
-        @SuppressWarnings("unused")
-        Collection<OsmPrimitive> sel = new LinkedList<OsmPrimitive>(testError.getPrimitives());
+        Collection<OsmPrimitive> sel = new LinkedList<>(testError.getPrimitives());
         Set<Node> nodes = new LinkedHashSet<>(OsmPrimitive.getFilteredList(sel, Node.class));
 
Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/MultipolygonTest.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/MultipolygonTest.java	(revision 11589)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/MultipolygonTest.java	(revision 11590)
@@ -669,7 +669,5 @@
         // add multipolygon in order to let user select something and fix the error
         if (!primitives.contains(r)) {
-            // Diamond operator does not work with Java 9 here
-            @SuppressWarnings("unused")
-            List<OsmPrimitive> newPrimitives = new ArrayList<OsmPrimitive>(primitives);
+            List<OsmPrimitive> newPrimitives = new ArrayList<>(primitives);
             newPrimitives.add(0, r);
             return newPrimitives;