code: public static <K, V> Map<K, V> plus(Map<K, V> self, Collection<? extends Map.Entry<? extends K, ? extends V>> entries) {
          Map<K, V> map = cloneSimilarMap(self);
          putAll(map, entries);
          return map;
      }
docs: Returns a new <code>Map</code> containing all entries from <code>self</code> and <code>entries</code>,
  giving precedence to <code>entries</code>.  Any keys appearing in both Maps
  will appear in the resultant map with values from the <code>entries</code>
  operand. If <code>self</code> map is one of TreeMap, LinkedHashMap, Hashtable
  or Properties, the returned Map will preserve that type, otherwise a HashMap will
  be returned.
  
  @param self    a Map
  @param entries a Collection of Map.Entry items to be added to the Map.
  @return a new Map containing all key, value pairs from self and entries
  @since 1.6.1