Extend test for empty weights

MultiSubDownloader/src/test/java/org/lodder/subtools/multisubdownloader/lib/control/subtitles/sorting/replacers/GroupReplacerTest.java

@@ -35,4 +35,20 @@ public void test_it_replaces_the_keyword_group_to_a_releasename() throws Excepti
     /* check if the weight is acme */
     assertTrue(definedWeights.containsKey("acme"));
   }
+
+  @Test
+  public void testEmptyWeights() throws Exception {
+    Release release = mock(Release.class);
+    when(release.getReleasegroup()).thenReturn("Acme");
+
+    HashMap<String, Integer> definedWeights = new HashMap<>();
+
+    replacer.replace(release, definedWeights);
+
+    /* check if the weight there is only one weight */
+    assertEquals(0, definedWeights.size());
+
+    /* check if the weight is acme */
+    assertFalse(definedWeights.containsKey("acme"));
+  }
 }