@Override
  public void writeTo(com.google.protobuf.CodedOutputStream output)
                      throws java.io.IOException {
    if (!com.google.protobuf.GeneratedMessage.isStringEmpty(url_)) {
      com.google.protobuf.GeneratedMessage.writeString(output, 1, url_);
    }
    if (!com.google.protobuf.GeneratedMessage.isStringEmpty(userId_)) {
      com.google.protobuf.GeneratedMessage.writeString(output, 2, userId_);
    }
    if (!com.google.protobuf.GeneratedMessage.isStringEmpty(sessionId_)) {
      com.google.protobuf.GeneratedMessage.writeString(output, 3, sessionId_);
    }
    if (timestamp_ != 0L) {
      output.writeInt64(4, timestamp_);
    }
    if (duration_ != 0L) {
      output.writeInt64(5, duration_);
    }
    if (!com.google.protobuf.GeneratedMessage.isStringEmpty(event_)) {
      com.google.protobuf.GeneratedMessage.writeString(output, 6, event_);
    }
    getUnknownFields().writeTo(output);
  }
<code>string event = 6;</code>
@return The bytes for event.
examples/client/src/main/java/com/clickhouse/examples/protos/UIEvent.java