Part of twisted.python View Source
Call functions with context.call({key: value}, func); func and functions that it calls will be able to use 'context.get(key)' to retrieve 'value'.
This is thread-safe.
| Class | ContextTracker | Undocumented | 
| Function | installContextTracker | Undocumented | 
| Class | _ThreadedContextTracker | Undocumented | 
| Class | _TLSContextTracker | Undocumented |