Custom stream filter keywords?

[seeess1]

Sorry, this isn't a bug but I wasn't sure where I should ask this question if not here. Huge thanks for sharing this repo. Just playing around with it and wanted to modify it to only pull in tweets that match my own specific set of keywords. What's the best way for me to do that?

Should I modify the last lines of twitter-to-pubsub.py? And then should I set the value for TWSTREAMMODE in twitter-stream.yaml to something other than "sample"? What else would I need to do? Create my own Docker image with the modified twitter-to-pubsub.py script?