def _get_requests_session():
    """Load requests lazily."""
    global requests_session
    if requests_session is not None:
        return requests_session
    import requests

    requests_session = requests.Session()
    adapter = requests.adapters.HTTPAdapter(
        max_retries=environments.PIPENV_MAX_RETRIES
    )
    requests_session.mount("https://pypi.org/pypi", adapter)
    return requests_session
Load requests lazily.