in java/dataflow-connector-examples/src/main/java/com/google/cloud/bigtable/dataflow/example/PubsubWordCount.java [100:107]
public void processElement(ProcessContext c) {
Instant timestamp = c.timestamp();
for (String word : c.element().split("[^a-zA-Z']+")) {
if (!word.isEmpty()) {
c.output(word + "|" + timestamp);
}
}
}