@Test
public void whenExtensionIsRecognized_returnsTypeForFile() {

    assertEquals("text/xml", mapper.map("file.xml"));
    assertEquals("audio/3gpp", mapper.map("file.3gpp"));
    assertEquals("video/3gpp", mapper.map("file.3gp"));
    assertEquals("video/avi", mapper.map("file.avi"));
    assertEquals("audio/amr", mapper.map("file.amr"));
    assertEquals("text/csv", mapper.map("file.csv"));
    assertEquals("image/jpeg", mapper.map("file.jpg"));
    assertEquals("audio/mp3", mapper.map("file.mp3"));
    assertEquals("video/mp4", mapper.map("file.mp4"));
    assertEquals("audio/ogg", mapper.map("file.oga"));
    assertEquals("audio/ogg", mapper.map("file.ogg"));
    assertEquals("video/ogg", mapper.map("file.ogv"));
    assertEquals("audio/wav", mapper.map("file.wav"));
    assertEquals("video/webm", mapper.map("file.webm"));
    assertEquals("application/vnd.ms-excel", mapper.map("file.xls"));
}