code: public static String join(String[] array, String delimiter) {
          if (empty(array)) { return ""; }
          StringBuilder sb = new StringBuilder();
          join(sb, array, delimiter);
          return sb.toString();
      }
docs: Joins the items in array with a delimiter.
  
  @param array array of items to join.
  @param delimiter delimiter to insert between elements of array.
  @return string with array elements separated by delimiter. There is no trailing delimiter in the string.