@Test(expected = RepeatedDependencyDefinedException.class)
public void testCantOverwrite() {

  DependencyMap dependencyMap = new DependencyMap();
  DependencyKey<TestClass> key = DependencyKey.of(TestClass.class);
  TestClass value1 = new TestClass();
  TestClass value2 = new TestClass();
  dependencyMap.put(key, value1, mPutValidator);
  dependencyMap.put(key, value2, mPutValidator);
}