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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_repo_url():
 """Return the base URL for Gluon dataset and model repository."""

    default_repo = 'https://apache-mxnet.s3-accelerate.dualstack.amazonaws.com/'
    repo_url = os.environ.get('MXNET_GLUON_REPO', default_repo)
    if repo_url[-1] != '/':
        repo_url = repo_url+'/'
    return repo_url