@Test
public final void testBuildMessageFileListJsonShouldCreateEmptyJsonWhenDirectoryIsNotADirectory() {

    //GIVEN
    String expected = "{\"files\":[]}";
    given(file.list()).willReturn(null);
    //WHEN
    String actual = underTest.buildMessageFileListJson(file, 5);
    //THEN
    assertEquals(actual, expected);
}