code: func getCollectionConfigFromFile(ccFile string) ([]byte, error) {
  	fileBytes, err := ioutil.ReadFile(ccFile)
  	if err != nil {
  		return nil, errors.Wrapf(err, "could not read file '%s'", ccFile)
  	}
  
  	return getCollectionConfigFromBytes(fileBytes)
  }
docs: // getCollectionConfig retrieves the collection configuration
  // from the supplied file; the supplied file must contain a
  // json-formatted array of collectionConfigJson elements