@Test
public void invalidAttributeFailTest() {

    Mockito.when(transformationContext.contains("ATT")).thenReturn(true);
    Mockito.when(transformationContext.get("ATT")).thenReturn("");
    TOExecutionResult executionResult = new PomFile("ATT").execution(transformedAppFolder, transformationContext);
    assertEquals(executionResult.getType(), TOExecutionResult.Type.ERROR);
    assertEquals(executionResult.getException().getClass(), TransformationOperationException.class);
    assertEquals(executionResult.getException().getMessage(), "Transformation context attribute ATT is not a Model object, but java.lang.String");
}