code: func (api UsersAPI) usernameGet(w http.ResponseWriter, r *http.Request) {
  	var respBody User
  	json.NewEncoder(w).Encode(&respBody)
  	// uncomment below line to add header
  	// w.Header().Set("key","value")
  }
docs: // usernameGet is the handler for GET /users/{username}
  // Get information on a specific user