code: @SafeVarargs
      public static <T> T mode(final T... items) {
          if (ArrayUtils.isNotEmpty(items)) {
              final HashMap<T, MutableInt> occurrences = new HashMap<>(items.length);
              for (final T t : items) {
                  final MutableInt count = occurrences.get(t);
                  if (count == null) {
                      occurrences.put(t, new MutableInt(1));
                  } else {
                      count.increment();
                  }
              }
              T result = null;
              int max = 0;
              for (final Map.Entry<T, MutableInt> e : occurrences.entrySet()) {
                  final int cmp = e.getValue().intValue();
                  if (cmp == max) {
                      result = null;
                  } else if (cmp > max) {
                      max = cmp;
                      result = e.getKey();
                  }
              }
              return result;
          }
          return null;
      }
docs: Find the most frequently occurring item.
  
  @param <T> type of values processed by this method
  @param items to check
  @return most populous T, {@code null} if non-unique or no items supplied
  @since 3.0.1