text: """Define spies."""
  from txtool import (
      database, )
  
  
  class Session:
      """Spy session for test."""
      def __init__(self):
          self.last_stmt = None
  
      def execute(self, stmt: str):
          self.last_stmt = stmt
          return None
  
  class SessionMaker:
      """Return a spy session."""
      def __call__(self):
          return Session()
  
  
  class Engine(database.Engine):
      """Test engine, no connection inside."""
      def __init__(self):
          super().__init__(SessionMaker())
  