ConcurrentMap<K, V> map = Maps.newConcurrentMap();
    map.put(key, value);
    return map;
  }

  @Generates
  static <K extends Comparable<? super K>, V> SortedMap<K, V> generateSortedMap(
      K key, @Nullable V value) {
    return generateNavigableMap(key, value);
  }

  @Generates
  static <K extends Comparable<? super K>, V> NavigableMap<K, V> generateNavigableMap(

    ConcurrentMap<K, V> map = Maps.newConcurrentMap();
    map.put(key, value);
    return map;
  }

  @Generates
  static <K extends Comparable<? super K>, V> SortedMap<K, V> generateSortedMap(
      K key, @Nullable V value) {
    return generateNavigableMap(key, value);
  }

  @Generates
  static <K extends Comparable<? super K>, V> NavigableMap<K, V> generateNavigableMap(