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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 _ensure_html_response(url, session):
 # type: (str, PipSession) -> None """Send a HEAD request to the URL, and ensure the response contains HTML. Raises `_NotHTTP` if the URL is not available for a HEAD request, or `_NotHTML` if the content type is not text/html. """

    scheme, netloc, path, query, fragment = urllib_parse.urlsplit(url)
    if scheme not in {'http', 'https'}:
        raise _NotHTTP()

    resp = session.head(url, allow_redirects=True)
    resp.raise_for_status()

    _ensure_html_header(resp)