code: public static void notEmpty(Map map, String message) {
          if (MapUtils.isEmpty(map)) {
              throw new IllegalArgumentException(message);
          }
      }
docs: Assert that a Map has entries; that is, it must not be {@code null}
  and must have at least one entry.
  <pre class="code">Assert.notEmpty(map, "Map must have entries");</pre>
  
  @param map the map to check
  @param message the exception message to use if the assertion fails
  @throws java.lang.IllegalArgumentException if the map is {@code null} or has no entries