@Test
public void getListOfChildren_null_children() {

    final File mockFile = Mockito.mock(File.class);
    Mockito.when(mockFile.exists()).thenReturn(true);
    Mockito.when(mockFile.isDirectory()).thenReturn(true);
    Mockito.when(mockFile.listFiles()).thenReturn(null);
    final File[] result = cut.getListOfChildren(mockFile);
    Assert.assertEquals(0, result.length);
}