Method _set_default_branch

src/ghstack/github_fake.py:453–458

(
        self, owner: str, name: str, input: SetDefaultBranchInput
    )

    # NB: This may have a payload, but we don't
    # use it so I didn't bother constructing it.
    def _set_default_branch(
        self, owner: str, name: str, input: SetDefaultBranchInput
    ) -> None:
        state = self.state
        repo = state.repository(owner, name)
        repo.defaultBranchRef = repo._make_ref(state, input["default_branch"])

    def rest(self, method: str, path: str, **kwargs: Any) -> Any:
        if method == "get":