### Question:
WorldObject extends EventExecutor { public void setWorld(World world) { if (this.world != null) throw new IllegalArgumentException("The world has already been set for this object."); this.world = world; } WorldObject();  WorldObject(String name); Angle getAngle(); void setAngle(Angle angle); Vector2D getVector2D(); void setVector2D(Vector2D vector2D); int getResourceID(); void setResourceID(int resourceID); int getId(); void setId(int id); HashMap<String, Object> getProperties(); World getWorld(); void setWorld(World world); int getZoneID(); void setZoneID(int zoneID); String getName(); void setName(String name); @Override String toString(); @Override boolean equals(Object o); @Override int hashCode();  }### Answer:
@Test public void testSetWorld() throws Exception { Assert.assertTrue(world == worldObject.getWorld()); }