public void testSeparatorsToUnix() {
        assertEquals(null, FilenameUtils.separatorsToUnix(null));
        assertEquals("/a/b/c", FilenameUtils.separatorsToUnix("/a/b/c"));
        assertEquals("/a/b/c.txt", FilenameUtils.separatorsToUnix("/a/b/c.txt"));
        assertEquals("/a/b/c", FilenameUtils.separatorsToUnix("/a/b\\c"));
        assertEquals("/a/b/c", FilenameUtils.separatorsToUnix("\\a\\b\\c"));
        assertEquals("D:/a/b/c", FilenameUtils.separatorsToUnix("D:\\a\\b\\c"));
}