title: Go error: Cannot use argument (type []string) as type string in argument
body: <p>Trying to get acquainted with go. I want to do something like this:</p>
  
  <pre><code>func validation(){
      headers := metadata.New(map[string]string{"auth":"", "abc": "", "xyz" : ""})
      token := headers["auth"]
  
      data.Add("cookie", token)
  }
  </code></pre>
  
  <p>I am getting the following error : <code>cannot use token (type []string) as type string in argument to data.Add</code>. Has this error got to do anything with the metadata(map) I have inside the function? </p>