You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: nodeshutdown_manager_linux.go
    path of file: ./repos/kubeedge/vendor/k8s.io/kubernetes/pkg/kubelet/nodeshutdown
    
    the code of the file until where you have to start completion: //go:build linux
// +build linux

/*
Copyright 2020 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// Package nodeshutdown can watch for node level shutdown events and trigger graceful termination of pods running on the no
    
func migrateConfig(shutdownGracePeriodRequested, shutdownGracePeriodCriticalPods time.Duration) []kubeletconfig.ShutdownGracePeriodByPodPriority {
	if shutdownGracePeriodRequested == 0 {
		return nil
	}
	defaultPriority := shutdownGracePeriodRequested - shutdownGracePeriodCriticalPods
	if defaultPriority < 0 {
		return nil
	}
	criticalPriority := shutdownGracePeriodRequested - defaultPriority
	if criticalPriority < 0 {
		return nil
	}
	return []kubeletconfig.ShutdownGracePeriodByPodPriority{
		{
			Priority:                   scheduling.DefaultPriorityWhenNoDefaultClassExists,
			ShutdownGracePeriodSeconds: int64(defaultPriority / time.Second),
		},
		{
			Priority:                   scheduling.SystemCriticalPriority,
			ShutdownGracePeriodSeconds: int64(criticalPriority / time.Second),
		},
	}
}