### Question:
TiledLayer implements Comparable<TiledLayer> { public int[] getTileIDs() { if (this.tileIDs == null) { throw new IllegalStateException("tileIDs wasnt set before, call setTileIDs() first."); } return tileIDs; } TiledLayer(String name, int width, int height, float opacity, boolean visible, float offsetx, float offsety, int floor, int renderOrder); void setTileIDs(int[] tileIDs); void addBoolProperty(String key, boolean value); void addIntProperty(String key, int value); void addFloatProperty(String key, float value); void addStringProperty(String key, String value); String getName(); int getWidth(); int getHeight(); float getOpacity(); boolean isVisible(); float getOffsetx(); float getOffsety(); int[] getTileIDs(); int getFloor(); int getRenderOrder(); @Override int compareTo(TiledLayer o);  }### Answer:
@Test (expected = IllegalStateException.class) public void testGetNullTileIDs () { TiledLayer layer = new TiledLayer("test", 10, 20, 1, true, 30, 40, 1, 1); layer.getTileIDs(); }
@Test public void testGetTileIDs () { TiledLayer layer = new TiledLayer("test", 10, 20, 1, true, 30, 40, 1, 1); layer.setTileIDs(new int[10 * 20]); assertNotNull(layer.getTileIDs()); assertEquals(200, layer.getTileIDs().length); }