@Test
public void testGetLogFileNames() {

    Collection<File> files = getFileCollection();
    Collection<String> expectedNames = new ArrayList<>();
    expectedNames.add("a");
    expectedNames.add("b");
    expectedNames.add("c");
    given(fileUtils.getFilesWithExtension(LOG_PATH, LOG_EXTENSION)).willReturn(files);
    //WHEN
    Collection<String> result = underTest.getLogFileNames();
    //THEN
    assertEquals(expectedNames, result);
}