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

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