<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def manifest_is_media_type(response, media_type):
 """ Attempt to confirm the returned manifest is of a given media type :param response: a requests.Response :param media_type: media_type (str), or None to confirm the media type cannot be guessed """

    try:
        received_media_type = response.headers['Content-Type']
    except KeyError:
        # Guess media type from content
        logger.debug("No Content-Type header; inspecting content")
        received_media_type = guess_manifest_media_type(response.content)
        logger.debug("guessed media type: %s", received_media_type)

    if received_media_type is None:
        return media_type is None

    # Only compare prefix as response may use +prettyjws suffix
    # which is the case for signed manifest
    response_h_prefix = received_media_type.rsplit('+', 1)[0]
    request_h_prefix = media_type.rsplit('+', 1)[0]
    return response_h_prefix == request_h_prefix