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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 parse_authorization_header(authorization_header):
 """Parse an OAuth authorization header into a list of 2-tuples"""

    auth_scheme = 'OAuth '.lower()
    if authorization_header[:len(auth_scheme)].lower().startswith(auth_scheme):
        items = parse_http_list(authorization_header[len(auth_scheme):])
        try:
            return list(parse_keqv_list(items).items())
        except (IndexError, ValueError):
            pass
    raise ValueError('Malformed authorization header')