code: func ConfigFromBackend(coreBackend ...core.ConfigBackend) (fab.EndpointConfig, error) {
  
  	config := &EndpointConfig{
  		backend: lookup.New(coreBackend...),
  	}
  
  	if err := config.loadEndpointConfiguration(); err != nil {
  		return nil, errors.WithMessage(err, "network configuration load failed")
  	}
  
  	//print deprecated warning
  	detectDeprecatedNetworkConfig(config)
  
  	return config, nil
  }
docs: //ConfigFromBackend returns endpoint config implementation for given backend