title: AssertJ: Assert if list is sorted inversely or in descending order
body: <p>I'm using AssertJ for my tests and I noticed there's a method for checking if a <code>List&lt;T&gt;</code> is sorted:</p>
  
  <pre><code>public static &lt;T&gt; void sorted(final List&lt;T&gt; actual) {
      try {
          assertThat(actual).isSorted();
      } catch (AssertionError e) {
          LOGGER.error(e.getMessage(), e);
          throw e;
      }
  }
  </code></pre>
  
  <p>Is there a way to check if the list is sorted in descending order?</p>
  
  <p>I know guava provides <code>Ordering.natural().reverse().isOrdered(values)</code> but I want to take advantage of AssertJ's assert messages as it really helps a lot in debugging e.g.</p>
  
  <pre><code>group is not sorted because element 5:
   &lt;"4000366190001391"&gt;
  is not less or equal than element 6:
   &lt;"4000206280001394"&gt;
  group was:
   &lt;["4000206280001363",
      "4000206280001364",
      "4000206280001365",
      "4000206280001373",
      "4000206280001388",
      "4000366190001391",
      "4000206280001394",
      "4000366190001401",
      "4000206280001403",
      "4000206280001405",
       ....]&gt;
  </code></pre>