code: def validate(self) -> None:
      logging.info(
          f"Ensure that a random selection of documents don't have '{self.field_name}' field"
      )
  
      check_documents(DocCls=CachedResponseDocument, sample_size=10)
  
imports: import logging
  from collections.abc import Mapping
  from typing import Any, Optional
  from libcommon.queue import JobDocument
  from libcommon.simple_cache import CachedResponseDocument
  from mongoengine.connection import get_db
  from mongodb_migration.check import check_documents
  from mongodb_migration.migration import BaseCacheMigration, BaseQueueMigration, CacheMigration, IrreversibleMigrationError, MetricsMigration, QueueMigration
label_desc: Use image node_id 4 for calling the MigrationRemoveFieldFromCache obj's underlying member method code with example usage: obj.validate() without return types