Perform a Yelp Review Search based on a location specifier.

        Args:
          location - textual location specifier of form: "address, neighborhood, city, state or zip, optional country"
          cc       - ISO 3166-1 alpha-2 country code. (Optional)
          radius   - search radius (in miles) (Optional)
          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)

def by_location(self, location, cc=None, radius=None, term=None, num_biz_requested=None, category=None):
        """
        Perform a Yelp Review Search based on a location specifier.

        Args:
          location - textual location specifier of form: "address, neighborhood, city, state or zip, optional country"
          cc       - ISO 3166-1 alpha-2 country code. (Optional)
          radius   - search radius (in miles) (Optional)
          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)
        """

        header, content = self._http_request(
            self.BASE_URL, 
            location = location, 
            cc = cc,
            radius = radius,
            term = term,
            num_biz_requested = num_biz_requested
        )		
        return json.loads(content)