def by_geopoint(self, lat, long, radius, term=None, num_biz_requested=None, category=None):
header, content = self._http_request(<EOL>self.BASE_URL,<EOL>lat    = lat, <EOL>long   = long, <EOL>radius = radius, <EOL>term   = None, <EOL>num_biz_requested = None<EOL>)  <EOL>return json.loads(content)<EOL>
Perform a Yelp Review Search based on a geopoint and radius tuple.

Args:
  lat      - geopoint latitude 
  long     - geopoint longitude  
  radius   - search radius (in miles)
  term     - Search term to filter by (Optional)
  num_biz_requested - Maximum number of matching results to return (Optional)
  category - '+'-seperated list of categories to filter by. See
http://www.yelp.com/developers/documentation/category_list
                          for list of valid categories. (Optional)