old_contents: from graphene.commands.command import Command
  
  class ExitCommand(Command):
      def __init__(self):
          pass
  
new_contents: from graphene.commands.command import Command
  
  class ExitCommand(Command):
      def __init__(self):
          pass
  
      def execute(self, storage_manager, timer=None):
          # This should never be used anyway.
          pass
  
subject: Fix EXIT command to have execute method for abstract class