code: def _get_instance_plans(self, packing_plan, container_id):
      
      this_container_plan = None
      for container_plan in packing_plan.container_plans:
        if container_plan.id == container_id:
          this_container_plan = container_plan
  
      # When the executor runs in newly added container by `heron update`,
      # there is no plan for this container. In this situation,
      # return None to bypass instance processes.
      if this_container_plan is None:
        return None
      return this_container_plan.instance_plans
docs: For the given packing_plan, return the container plan with the given container_id. If protobufs
      supported maps, we could just get the plan by id, but it doesn't so we have a collection of
      containers to iterate over.