code: public static <K, V> Map<K, V> putAll(Map<K, V> self, Collection<? extends Map.Entry<? extends K, ? extends V>> entries) {
          for (Map.Entry<? extends K, ? extends V> entry : entries) {
              self.put(entry.getKey(), entry.getValue());
          }
          return self;
      }
docs: Provides an easy way to append multiple Map.Entry values to a Map.
  
  @param self    a Map
  @param entries a Collection of Map.Entry items to be added to the Map.
  @return the same map, after the items have been added to it.
  @since 1.6.1