Method forEach

guava/src/com/google/common/collect/Maps.java:941–946

(BiConsumer<? super K, ? super V> action)

    }

    @Override
    public void forEach(BiConsumer<? super K, ? super V> action) {
      checkNotNull(action);
      // avoids allocation of entries
      backingSet().forEach(k -> action.accept(k, function.apply(k)));
    }
  }

  static <K extends @Nullable Object, V extends @Nullable Object>