@Test
public void shouldEnableChangeButtonIfValueNotEmpty() throws Exception {
when(view.getValue()).thenReturn(VAR_VALUE);
presenter.onVariableValueChanged();
verify(view).setEnableChangeButton(eq(!DISABLE_BUTTON));
}
@Test
public void shouldDisableChangeButtonIfNoValue() throws Exception {
when(view.getValue()).thenReturn(EMPTY_VALUE);
presenter.onVariableValueChanged();
verify(view).setEnableChangeButton(eq(DISABLE_BUTTON));
}