def get_reference_repository(self, reference: Optional[Path], repo: str) -> Optional[Path]:
        """
        Returns a repository to use in clone command, if there is one to be referenced.
        Either provided by the user of generated from already cloned branches (master is preferred).

        :param reference: Path to a local repository provided by the user or None.
        :param repo: Reference for which remote repository.
        """
        if reference is not None:
            return reference.absolute()

        repo_path = self.get_path_to_repo(repo)

        if not repo_path.exists():
            return None

        master = repo_path / "master"

        if master.exists() and master.is_dir():
            return master

        for existing_branch in repo_path.iterdir():
            if not existing_branch.is_dir():
                continue

            return existing_branch.resolve()

        return None
Returns a repository to use in clone command, if there is one to be referenced.
        Either provided by the user of generated from already cloned branches (master is preferred).

        :param reference: Path to a local repository provided by the user or None.
        :param repo: Reference for which remote repository.