code: func classifyBundledFile(name string) (bundleDirType, bool) {
  	if !IsContentFile(name) {
  		return bundleNot, false
  	}
  	if strings.HasPrefix(name, "_index.") {
  		return bundleBranch, true
  	}
  
  	if strings.HasPrefix(name, "index.") {
  		return bundleLeaf, true
  	}
  
  	return bundleNot, true
  }
docs: // Returns the given file's name's bundle type and whether it is a content
  // file or not.