class Worker:
    """
    The Worker Object
    """
    def __init__(
        self,
        name: str,
        max_runs: int | None = None,
        debug: bool = False,
        handle_kill: bool = True,
        config: ClientConfig = None,
        context_class: Type[Context] = Context,
    ):
        ...
        self._context_cls = context_class


    def handle_start_step_run(self, action: Action):
        """
        Handles the start step run action
        """
        action_name = action.action_id
        context = self._context_cls(action, self.client)
       ...

    def handle_start_group_key_run(self, action: Action):
        """
        Handles the start group key run action
        """
        action_name = action.action_id
        context = self._context_cls(action, self.client)
        ....

class AdminClientImpl:
   ...
   def run_workflow(
        self,
        workflow_name: str,
        input: any,
        options: TriggerWorkflowOptions = None,
    ):
        """
        Handle the run workflow method
        """
        try:
            payload_data = json_serializer.dumps(input)

            try:
                meta = None if options is None else options["additional_metadata"]  # < raises KeyError Here
                # meta = None if options is None else options.get("additional_metadata") 
   

class Context:
   ...
    def spawn_workflow(self, workflow_name: str, input: dict = None, key: str = None):
        """
        Spawns a workflow
        """
        input = input or {}
        workflow_run_id = self.action.workflow_run_id
        step_run_id = self.action.step_run_id
        
        # Since `additional_metadata` doesn't exist here
        options: ScheduleTriggerWorkflowOptions = {
            "parent_id": workflow_run_id,
            "parent_step_run_id": step_run_id,
            "child_key": key,
            "child_index": self.spawn_index,
        }

        self.spawn_index += 1
        child_workflow_run_id = self.client.admin.run_workflow(
            workflow_name, input, options
        )