LANG-1267: Add test showing that XXX does work when specifing formats

src/test/java/org/apache/commons/lang3/time/FastDateFormatTest.java

@@ -319,5 +319,10 @@ public class FastDateFormatTest {
 
         dateAsString = FastDateFormat.getInstance("dd/MM/yyyy", utc, Locale.US).format(date);
         Assert.assertEquals("17/08/292278994", dateAsString);
-    }  
+    }
+
+    @Test
+    public void testLANG_1267() throws Exception {
+        FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+    }
 }