code: def geo_haystack(self, name, bucket_size):
          
          self.components.append((name, 'geoHaystack'))
          self.__bucket_size = bucket_size
          return self
docs: Create a Haystack index.  See:
              http://www.mongodb.org/display/DOCS/Geospatial+Haystack+Indexing
  
              :param name: Name of the indexed column
              :param bucket_size: Size of the haystack buckets (see mongo docs)