`os.file` has the following function: ``` // ReadFrom implements io.ReaderFrom. func (f *File) ReadFrom(r io.Reader) (n int64, err error) { if err := f.checkValid("write"); err != nil { return 0, err } n, handled, e := f.readFrom(r) if !handled { return genericReadFrom(f, r) // without wrapping } return n, f.wrapErr("write", e) } ``` Is it something we can have in `afero`?