Delete only one edge between two node in Follow list

Users Dgraph
1

Hi
#golang #go #dgo
I use a function by name unset_action for delete an edge between two nodes.
but when I below code it deletes all of the edges.

by example :
I want delete Follow edge from “mehrdad” to “mhb8898” but too delete the Follow edge from “mehrdad” tor “ali” .
I want delete just Follow edge from “mehrdad” to “mhb8898” (only one edge from Follow list)

my code :

func unset_action(action, user1 ,user2 string ,dg *dgo.Dgraph, ctx context.Context) {
    mu := &api.Mutation{
        CommitNow: true,
    }

    var resp struct {
        Find []struct{
            UID string `json:"uid"`
        } `json:"find"`
    }

    // find user 1
    person1, err := dg.NewTxn().Query(context.Background(), fmt.Sprintf("{find(func : allofterms(UrlName , %v)){uid}}", user1))
    if err != nil {
        log.Fatal(err)
    }

    // parse response json user 1
    err = json.Unmarshal(person1.Json , &resp)
    if err != nil {
        log.Fatal(err)
    }

    uid1 := resp.Find[0].UID

    // find user 2
    person2, err := dg.NewTxn().Query(context.Background(), fmt.Sprintf("{find(func : allofterms(UrlName , %v)){uid}}", user2))
    if err != nil {
        log.Fatal(err)
    }

    // parse response json user 2
    err = json.Unmarshal(person2.Json , &resp)
    if err != nil {
        log.Fatal(err)
    }

    // uid2 := resp.Find[0].UID

    // query
    // query := fmt.Sprintf("<%v> <%v> <%v> . ",uid1 , action , uid2)

    // unset action
    dgo.DeleteEdges(mu, uid1, "Follow" )

    _, err = dg.NewTxn().Mutate(ctx, mu)
    if err != nil {
        log.Fatal(err)
    }
}

Can you help me?!
thanks .