@Test
  public void retrieveNonIndexedChat_ShouldAddNewIndexEntryAfterRetrievalAttempt() {
    FolderIndexMock folderIndex = new FolderIndexMock();
    IndexedSkypeMailFolder indexedGmailFolder_SUBJECT = createIndexedSkypeMailFolder(folderIndex);

    SkypeChat nonIndexedSkypeChat =
        SkypeApiMock.produceChatMock("#is-not-indexed", "not", "indexed");

    Assert.assertNull(folderIndex.getSignatureFor("#is-not-indexed"));

    indexedGmailFolder_SUBJECT.retrieveMessageEntryFor(nonIndexedSkypeChat);

    String sig = folderIndex.getSignatureFor("#is-not-indexed");
    Assert.assertEquals(nonIndexedSkypeChat.getBodySignature(), sig);
  }