### Question:
MutableBinaryTreeImplKeyMapping implements KeyMapping<MutableBinaryTree> { @Override public Class<MutableBinaryTree> forClass() { return MutableBinaryTree.class; }  @Override Class<? extends MutableBinaryTree> getConcreteClass(); @Override Class<MutableBinaryTree> forClass();  }### Answer:
@Test public void forClass() { final MutableBinaryTreeImplKeyMapping mapping = new MutableBinaryTreeImplKeyMapping(); assertEquals(MutableBinaryTree.class, mapping.forClass()); }