docs: public static String join(String separator, Collection<String> stringsToJoin) {
          StringBuilder builder = new StringBuilder();
          // Check if there is at least 1 element then use do/while to avoid trailing separator
          int index = stringsToJoin.size();
          for (String str : stringsToJoin) {
              index--;
              if (str != null) {
                  builder.append(str);
                  if (index > 0) {
                      builder.append(separator);
                  }
              }
          }
          return builder.toString();
      }