not 75% of all code but 75 of all code that is doing anything with meaningful practically. the classic example of a simple copyFile func.

  func CopyFile(src, dst string) error {
    r, err := os.Open(src)
    if err != nil {
     return err
    }
    defer r.Close()

   w, err := os.Create(dst)
    if err != nil {
     return err
    }
    defer w.Close()

   if _, err := io.Copy(w, r); err != nil {
     return err
    }
    if err := w.Close(); err != nil {
     return err
    }
  }