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: filter.go
    path of file: ./repos/buildkit/vendor/github.com/vishvananda/netlink
    
    the code of the file until where you have to start completion: package netlink

import (
	"fmt"
	"net"
)

type Filter interface {
	Attrs() *FilterAttrs
	Type() string
}

// FilterAttrs represents a netlink filt
    
func (a MirredAct) String() string {
	switch a {
	case TCA_EGRESS_REDIR:
		return "egress redir"
	case TCA_EGRESS_MIRROR:
		return "egress mirror"
	case TCA_INGRESS_REDIR:
		return "ingress redir"
	case TCA_INGRESS_MIRROR:
		return "ingress mirror"
	}
	return "unknown"
}