Deletes a branch, but leaves the commits themselves intact. In other
        words, those commits can still be accessed via commit IDs and other
        branches they happen to be on.

        Params:
        * repo_name: The name of the repo.
        * branch_name: The name of the branch to delete.

def delete_branch(self, repo_name, branch_name):
        """
        Deletes a branch, but leaves the commits themselves intact. In other
        words, those commits can still be accessed via commit IDs and other
        branches they happen to be on.

        Params:
        * repo_name: The name of the repo.
        * branch_name: The name of the branch to delete.
        """
        res = proto.DeleteBranchRequest(repo=Repo(name=repo_name), branch=branch_name)
        self.stub.DeleteBranch(res, metadata=self.metadata)