how write protobuf file in golang like this map[string][]string

Question

I have a struct like this in golang:

type Request struct {
      Mark     string              
      RemoteIp string              
      Url      string              
      Header   map[string][]string 
      Body     []byte              
}

how to convert map[string][]string structure to protobuf message？ I've try out this, but wrong

map<string,   repeated string> Header = 4;