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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 fetch(url, timeout=5, userAgent=None, only_mime_types=None):
 """ Retrieves the raw content of the URL. """

    headers = {}
    if userAgent:
        headers['User-agent'] = str(userAgent)
    else:
        headers['User-agent'] = ua.random

    #request = Request(url=url, headers=headers)
    #response = urlopen(request, timeout=timeout)
    response = requests.get(url, headers=headers, timeout=timeout)

    # Return nothing of the content isn't one of the target mime-types.
    if only_mime_types:
        assert isinstance(only_mime_types, (tuple, list))
        # Check for mimetype by looking at pattern in the URL.
        # Not super accurate, but very fast.
        ct, mt_encoding = mimetypes.guess_type(url)
        # Then check for mimetype by actually requesting the resource and
        # looking at the response.
        # More accurate, but slower since we actually have to send a request.
        if not ct:
            response_info = response.info()
            ct = (response_info.getheader('Content-Type') or '').split(';')[0]
        #TODO:if still undefined, use magic.Magic(mime=True).from_file(url)?
        if ct not in only_mime_types:
            return
    try:
        #return response.read()
        return response.text
    except httplib.IncompleteRead as e:
        # This should rarely happen, and is often the fault of the server
        # sending a malformed response.
        #TODO:just abandon all content and return '' instead?
        return e.partial