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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 main(github_token, github_api_url, progress):
 """A CLI to easily manage GitHub releases, assets and references."""

    global progress_reporter_cls
    progress_reporter_cls.reportProgress = sys.stdout.isatty() and progress
    if progress_reporter_cls.reportProgress:
        progress_reporter_cls = _progress_bar
    global _github_token_cli_arg
    _github_token_cli_arg = github_token
    global _github_api_url
    _github_api_url = github_api_url