docs: public static String pathJoin(String... strings) {
      StringBuilder buffer = new StringBuilder();
      for (String string : strings) {
        if (string == null) {
          continue;
        }
        if (buffer.length() > 0) {
          boolean bufferEndsWithSeparator = buffer.toString().endsWith("/");
          boolean stringStartsWithSeparator = string.startsWith("/");
          if (bufferEndsWithSeparator) {
            if (stringStartsWithSeparator) {
              string = string.substring(1);
            }
          } else {
            if (!stringStartsWithSeparator) {
              buffer.append("/");
            }
          }
        }
        buffer.append(string);
      }
      return buffer.toString();
    }