code: func (r rpc) simulateRequest(endpoint string, method string) ([]byte, error) {
  	// Test files conform to replacing '/' in endpoint with '_'
  	fileName := strings.Replace(endpoint, "/", "_", -1)
  	// file names also have method type prepended to ensure uniqueness
  	filePath := basePath + "/test_data/" + method + "_" + fileName + ".json"
  	data, err := ioutil.ReadFile(filePath)
  	if err != nil {
  		return nil, err
  	}
  	return data, nil
  }
docs: // simulateRequest simulates a request by returning a sample JSON from file