source: class ApexTest {
  
      private Apex apexLanguage;
  
      @Test
      public void testCustomFileSuffixes() {
  
target:         Map<String, String> props = Maps.newHashMap();
          props.put(Apex.FILE_SUFFIXES_KEY, "cls,apex");
  
          Settings settings = new Settings();
          settings.addProperties(props);
  
          assertThat(apexLanguage.getFileSuffixes(), is(new String[]{"cls", "trigger"}));
      }
  
  }