func RequireDevices(s Subsystem, p Path, err error) error {
	if s.Name() == Devices {
		return ErrDevicesRequired
	}
	return ErrIgnoreSubsystem
}
RequireDevices requires the device subsystem but no others
package cgroups
import (
	"github.com/pkg/errors"
)
var (
	ErrIgnoreSubsystem = errors.New("skip subsystem")
	ErrDevicesRequired = errors.New("devices subsystem is required")
)
type InitOpts func(*InitConfig) error
type InitConfig struct {
	InitCheck InitCheck
}
func newInitConfig() *InitConfig {
	return &InitConfig{
		InitCheck: RequireDevices,
	}
}
type InitCheck func(Subsystem, Path, error) error
func AllowAny(s Subsystem, p Path, err error) error {
	return ErrIgnoreSubsystem
}