code: public StreamRecord<T> copy(T valueCopy) {
  		StreamRecord<T> copy = new StreamRecord<>(valueCopy);
  		copy.timestamp = this.timestamp;
  		copy.hasTimestamp = this.hasTimestamp;
  		return copy;
  	}
docs: Creates a copy of this stream record. Uses the copied value as the value for the new
  record, i.e., only copies timestamp fields.