Make sure nextTuple emits tuple with non-null values (#1000)

* Make sure nextTuple emits tuple with non-null values

* remove recursive emit call and reduce receive-timeout
1 file changed
tree: 9d61bc9b5763457e275089dbfb66282f8c58084f
  1. pulsar-client-kafka-compat/
  2. pulsar-spark/
  3. pulsar-storm/