def create_repo(self, repo_name, description=None):
        """
        Creates a new Repo object in PFS with the given name. Repos are the 
        top level data object in PFS and should be used to store data of a
        similar type. For example rather than having a single Repo for an
        entire project you might have separate Repos for logs, metrics,
        database dumps etc.
        
        Params:
        * repo_name: Name of the repo.
        * description: Repo description.
        """
        req = proto.CreateRepoRequest(repo=proto.Repo(name=repo_name), description=description)
        self.stub.CreateRepo(req, metadata=self.metadata)