@Override
    public String toString() {
      StringBuilder sb = new StringBuilder("exists_args(");
      boolean first = true;

      sb.append("interfaceName:");
      if (this.interfaceName == null) {
        sb.append("null");
      } else {
        sb.append(this.interfaceName);
      }
      first = false;
      sb.append(")");
      return sb.toString();
    }