| Class | TransportHooks | Dict-mapping hook name to a list of callables for transport hooks |
| Class | InstrumentedTransport | Instrumented transport class to test commands behavior |
| Class | ConnectionHookedTransport | Transport instrumented to inspect connections |
| Class | TestCaseWithConnectionHookedTransport | Undocumented |
| Function | _change_scheme_in | Undocumented |