pkg go/doc, func ToText //deprecated #51082
pkg io/ioutil, func NopCloser //deprecated #42026
pkg io/ioutil, func ReadAll //deprecated #42026
pkg io/ioutil, func ReadDir //deprecated #42026
pkg io/ioutil, func ReadFile //deprecated #42026
pkg io/ioutil, func TempDir //deprecated #42026
pkg io/ioutil, func TempFile //deprecated #42026
pkg io/ioutil, func WriteFile //deprecated #42026

	HasSubdir func(root, dir string) (rel string, ok bool)

	// ReadDir returns a slice of fs.FileInfo, sorted by Name,
	// describing the content of the named directory.
	// If ReadDir is nil, Import uses ioutil.ReadDir.
	ReadDir func(dir string) ([]fs.FileInfo, error)

	// OpenFile opens a file (not a directory) for reading.
	// If OpenFile is nil, Import uses os.Open.
	OpenFile func(path string) (io.ReadCloser, error)
}