code: public static void internAll(String[] strings) {
          for (int i = 0; i < strings.length; i++) {
              strings[i] = strings[i].intern();
          }
      }
docs: Replaces every element of the supplied string array with an interned
  copy as created by {@link String#intern()}.
  
  @param strings a {@link String[]}. Cannot be <code>null</code>.