code: func Create(name string, parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
  	driverFactory, ok := driverFactories[name]
  	if !ok {
  		return nil, InvalidStorageDriverError{name}
  	}
  	return driverFactory.Create(parameters)
  }
docs: // Create a new storagedriver.StorageDriver with the given name and
  // parameters. To use a driver, the StorageDriverFactory must first be
  // registered with the given name. If no drivers are found, an
  // InvalidStorageDriverError is returned