public Builder setUsers(JOutPiqi.userid_list value) {
        if (usersBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          users_ = value;
          onChanged();
        } else {
          usersBuilder_.setMessage(value);
        }
        bitField0_ |= 0x00000002;
        return this;
      }