Pub/Sub Admin -- create

Create topic
Create subscription for topic

Pub/Sub -- post and subscribe

Send or retrieve/ack one message at a time
Message Retrieval (acks one message at a time)
Send copies of message to topic

Pub/Sub -- batch pull

Retrieve messages from different subscriptions, and ack as a batch
Subscription1
Subscription2

Pub/Sub Admin -- delete

Delete topic
Delete subscription