### Question:
SaveDiagramSessionCommand extends AbstractClientSessionCommand<EditorSession> { @Override @SuppressWarnings("unchecked") public <V> void execute(final Callback<V> callback) { } SaveDiagramSessionCommand(); @Override @SuppressWarnings("unchecked") void execute(final Callback<V> callback); @Override boolean accepts(final ClientSession session);  }### Answer:
@Test public void testExecute() { command.execute(callback); verifyNoMoreInteractions(callback); }
@Test public void testExecute() { command.execute(); }
@Test public void testExecuteWithCallback() { command.execute(callback); Mockito.verifyNoMoreInteractions(callback); }