找不到类型InteractionCallback，并且atom正在删除导入语句

I am using the atom IDE, and for some reason whenever I add this to my imports:

"github.com/nlopes/slack"

And save the file, it removes the import. So I'm not sure why but it isn't finding the InteractionCallback type in the library?

I copied this code from the example:

func unmarshalSuggestionCallback(j string) (*InteractionCallback, error) {
    callback := &InteractionCallback{}
    if err := json.Unmarshal([]byte(j), &callback); err != nil {
        return nil, err
    }
    return callback, nil
}

I am getting this error:

undefined: InteractionCallback

How can I tell if my library I just downloaded has the type defined? Or am I referencing the type incorrectly?

Please use this command in your terminal: go get -u github.com/nlopes/slack

After that try to run this code:

package main

import (
    "encoding/json"
    "fmt"
    "github.com/nlopes/slack"
)

func unmarshalSuggestionCallback(j string) (*slack.InteractionCallback, error) {
    callback := &slack.InteractionCallback{}
    if err := json.Unmarshal([]byte(j), &callback); err != nil {
        return nil, err
    }
    return callback, nil
}

func main() {
    callback,_:=unmarshalSuggestionCallback(`{"type":"callback"}`)
    fmt.Println(callback.Type)
}

Everything should work fine, I have checked in my PC

You need to specify from which package InteractionCallback comes from, in your case its slack package - slack.InteractionCallback