Custom Test Framework using only OpenAPI?

Is it possible to develop a custom test framework using only the OpenAPI? That is, can I create my own test framework, write a plugin for it using the OpenAPI and expect to see it in the menu which appears when the user does ALT+ENTER over a class name? (ALT+ENTER is the default keyboard binding  which brings up the "create tests..." context menu).


Does anyone know for sure? It seems like the dialog which appears when you're selecting methods to write unit tests for is inaccessible using just the Open API, and therefore the source (Community) needs to be hacked in order for my new test framework to even appear as an option in that menu, much less run.