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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_or_create_environment(self, repo: str, branch: str, git_repo: Repo, repo_path: Path) -> str: # pragma: no cover """ Abstract method which must be implemented in subclasses, which must return a str path to a Python executable which will be used to run the script. See :meth:`BaseBackend.run <arca.BaseBackend.run>` to see arguments description. """

        raise NotImplementedError