public String getUserId() {
      Object ref = userId_;
      if (!(ref instanceof String)) {
        com.google.protobuf.ByteString bs =
            (com.google.protobuf.ByteString) ref;
        String s = bs.toStringUtf8();
        userId_ = s;
        return s;
      } else {
        return (String) ref;
      }
    }
<code>string user_id = 2;</code>
@return The userId.
examples/client/src/main/java/com/clickhouse/examples/protos/UIEvent.java