'Get are HEAD response for URL.
Here to help with testing and allow injecting another URL getter.
@param url: Full URL to the page which is retrieved.
@type url: L{str}
@return: The response for the HEAD method.
@rtype: urllib2 response or L{None}'

def _getURLAsHEAD(self, url):

    try:
        return urllib2.urlopen(HeadRequest(url))
    except Exception as e:
        print 'Error    opening    {}:    {}'.format(url, e)
        return None
