'Returns the image url from your profile
Shortcut for me/picture
:param size:
the type of the image to request, see facebook for available formats
:returns: string'

def my_image_url(self, size='large'):

    query_dict = QueryDict('', True)
    query_dict['type'] = size
    query_dict['access_token'] = self.access_token
    url = ('%sme/picture?%s' % (self.api_url, query_dict.urlencode()))
    return url
