code: def add_cache(self, object_type, cache_impl_name, maxsize, **kwargs):
          
          if object_type not in ZendeskObjectMapping.class_mapping:
              raise ZenpyException("No such object type: %s" % object_type)
          self.cache.mapping[object_type] = ZenpyCache(cache_impl_name, maxsize, **kwargs)
docs: Add a new cache for the named object type and cache implementation