To avoid getting lost in architectural decisions, I'll ask this with an analogous example:

lets say I wanted a Python class pattern like this: 

```
queue = TaskQueue(broker_conn)
queue.region("DFW").task(fn, "some arg") 

```

The question here is how do I get a design a class such that certain methods can be "chained" in this fashion.

`task()` would require access to the `queue` class instance attributes and the operations of `task` depends on the output of `region()`.

I see SQLalchemy does this (see below) but am having difficulty digging through their code and isolating this pattern.

```
query = db.query(Task).filter(Task.objectid==10100) 

```