What is the equivalent of Ports in py_trees

[KabadagiOmkar]

I've been looking for a good, idiomatic way to use behaviors as isolated functions that take input, and produce output. While exploring BehaviourTree.CPP, I found that its port functionality ports example aligns with what I need.

What would be the equivalent approach in py_trees?

I am really looking forward to using this in my next project but I am trying to understand the right way to approach this Input/Output problem instead of a whole global blackboard.