def _get_instance_plans(self, packing_plan, container_id):
this_container_plan = None<EOL>for container_plan in packing_plan.container_plans:<EOL><INDENT>if container_plan.id == container_id:<EOL><INDENT>this_container_plan = container_plan<EOL><DEDENT><DEDENT>if this_container_plan is None:<EOL><INDENT>return None<EOL><DEDENT>return this_container_plan.instance_plans<EOL>
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.