@Test
public void testGuessFormat_Gz() throws Exception {

    String filename = "data/xyz/bf3.xyz.gz";
    InputStream input = new BufferedInputStream(new GZIPInputStream(this.getClass().getClassLoader()
            .getResourceAsStream(filename)));
    IChemFormat format = factory.guessFormat(input);
    Assert.assertNotNull(format);
    // make sure the InputStream is properly reset
    BufferedReader reader = new BufferedReader(new InputStreamReader(input));
    String line = reader.readLine();
    Assert.assertNotNull(line);
    Assert.assertEquals("4", line);
    line = reader.readLine();
    Assert.assertNotNull(line);
    Assert.assertEquals("Bortrifluorid", line);
}