@Test
public void testHandleAttributeAddition_LockRHS() {

    popup.handleAttributeAddition(RuleAttributeWidget.LOCK_RHS);
    assertThat(model.attributes).isEmpty();
    assertThat(model.metadataList).containsExactly(new RuleMetadata(RuleAttributeWidget.LOCK_RHS, "true"));
    verify(refreshCommand).execute();
}