code: func (client *Client) GetApplicationEnvironment(appGUID string) (Environment, Warnings, error) {
  	request, err := client.newHTTPRequest(requestOptions{
  		URIParams:   internal.Params{"app_guid": appGUID},
  		RequestName: internal.GetApplicationEnvRequest,
  	})
  	if err != nil {
  		return Environment{}, nil, err
  	}
  
  	var responseEnvVars Environment
  	response := cloudcontroller.Response{
  		DecodeJSONResponseInto: &responseEnvVars,
  	}
  	err = client.connection.Make(request, &response)
  	return responseEnvVars, response.Warnings, err
  }
docs: // GetApplicationEnvironment fetches all the environment variables on
  // an application by groups.