code: def __len__(self):
      if self._cache is not None:
          return len(self._cache)
      else:
          return self.query.count()
  
file_path: aim/aim/storage/structured/sql_engine/utils.py
imports: from abc import ABCMeta
  from typing import Iterator, Collection, TypeVar, Union, Callable
  from sqlalchemy import text
label_desc: Use image node_id 5 for calling the ModelMappedCollection obj's underlying member method code with example usage: obj.__len__() and returns: len, self