@Test
public void testSerializeWithEmptyProperties(){

    String expected = "{}";
    PropertyFileDescriptor spyDescriptor = mock(PropertyFileDescriptor.class);
    when(spyDescriptor.eClass()).thenReturn(PropertiesPackage.Literals.PROPERTY_FILE_DESCRIPTOR);
    when(spyDescriptor.loadProperties()).thenReturn(PropertiesFactory.eINSTANCE.createPropertyFile());
    StringBuilder result = new StringBuilder();
    getFixture().serialize(spyDescriptor, result, 2);
    assertEquals(expected, result.toString());
}