### Description <!-- Describe the proposed or requested change, and explain the type of change. Is it a change to the protocol, to the documentation, or something else? --> An Activity should be able to handle being called without being a subscriber callback. That is, you should be able to call an activity. Example: ``` class MyActivity(Activity): pass activity = MyActivity(...) activity() # Stuff happens ``` ### Motivation Sometimes an activity can be triggered without listening on events, for example when creating a tool that sends activity triggered,started,finished. ### Exemplification <!-- Can you think of a concrete example illustrating the impact and value of the change? --> Activities should be allowed to be used as activities started and not just activities triggered. ### Benefits <!-- What would the benefits of introducing this change be? --> Ease of use. ### Possible Drawbacks <!-- What are the possible side-effects or negative impacts of the change, and why are they outweighed by the benefits? --> Maybe pinning too much functionality to the activity object.