### Question:
CoLocationConstraint { public AbstractID getGroupId() { return this.group.getId(); } CoLocationConstraint(CoLocationGroup group); SharedSlot getSharedSlot(); AbstractID getGroupId(); boolean isAssigned(); boolean isAssignedAndAlive(); TaskManagerLocation getLocation(); void setSharedSlot(SharedSlot newSlot); void lockLocation(); void lockLocation(TaskManagerLocation taskManagerLocation); void setSlotRequestId(@Nullable SlotRequestId slotRequestId); @Nullable SlotRequestId getSlotRequestId(); @Override String toString();  }### Answer:
@Test public void testCreateConstraints() { try { JobVertexID id1 = new JobVertexID(); JobVertexID id2 = new JobVertexID(); JobVertex vertex1 = new JobVertex("vertex1", id1); vertex1.setParallelism(2); JobVertex vertex2 = new JobVertex("vertex2", id2); vertex2.setParallelism(3); CoLocationGroup group = new CoLocationGroup(vertex1, vertex2); AbstractID groupId = group.getId(); assertNotNull(groupId); CoLocationConstraint constraint1 = group.getLocationConstraint(0); CoLocationConstraint constraint2 = group.getLocationConstraint(1); CoLocationConstraint constraint3 = group.getLocationConstraint(2); assertFalse(constraint1 == constraint2); assertFalse(constraint1 == constraint3); assertFalse(constraint2 == constraint3); assertEquals(groupId, constraint1.getGroupId()); assertEquals(groupId, constraint2.getGroupId()); assertEquals(groupId, constraint3.getGroupId()); } catch (Exception e) { e.printStackTrace(); fail(e.getMessage()); } }