@Test
  public void testUpdatePosting() throws DataNotFoundException {
    String newTitle = "The new title.";
    String newTags = "#update";

    postingService.writePosting("first_blog", testMixedPosting1);

    Posting originPosting = postingService.findPosting("first_blog", 1);
    originPosting.setContents(mixedContent2);
    originPosting.setTitle(newTitle);
    originPosting.setTags(newTags);

    postingService.updatePosting("first_blog", originPosting);

    Posting changedPosting = postingService.findPosting("first_blog", 1);
    assertEquals(newTitle, changedPosting.getTitle());
    assertEquals(newTags, changedPosting.getTags());
    PostingContent changedContents = changedPosting.getContents();
    assertEquals(mixedContent2.getTextContent(), changedContents.getTextContent());
    String[] newFiles = mixedContent2.getFilePaths();
    String[] changedFiles = changedContents.getFilePaths();
    for (int i = 0; i < newFiles.length; i++) {
      assertEquals(newFiles[i], changedFiles[i]);
    }

    postingService.removePosting("first_blog", 1);
  }