// Pipeline demonstrates the use of a Group to implement a multi-stage // pipeline: a version of the MD5All function with bounded parallelism from // https://blog.golang.org/pipelines. func ExampleGroup_pipeline() { … } type result … // MD5All reads all the files in the file tree rooted at root and returns a map // from file path to the MD5 sum of the file's contents. If the directory walk // fails or any read operation fails, MD5All returns an error. func MD5All(ctx context.Context, root string) (map[string][md5.Size]byte, error) { … }