@Test
public void getSpecificResultFilename() {

    MultiplePdfSourceMultipleOutputParameters victim = new MultiplePdfSourceMultipleOutputParameters();
    victim.addSpecificResultFilenames(Arrays.asList("one", "two", "three.json"));
    assertEquals("one.txt", victim.getSpecificResultFilename(1, ".txt"));
    assertEquals("two.pdf", victim.getSpecificResultFilename(2));
    assertEquals("three.json", victim.getSpecificResultFilename(3, ""));
    assertNull(victim.getSpecificResultFilename(10));
}