t.Errorf("instantiated %q, want %q", got, want)
	}
}

// Copied from errors.go.
func stripAnnotations(s string) string {
	var buf strings.Builder
	for _, r := range s {
		// strip #'s and subscript digits
		if r < '₀' || '₀'+10 <= r { // '₀' == U+2080
			buf.WriteRune(r)
		}
	}
	if buf.Len() < len(s) {
		return buf.String()
	}
	return s

		t.Errorf("instantiated %q, want %q", got, want)
	}
}

// Copied from errors.go.
func stripAnnotations(s string) string {
	var buf strings.Builder
	for _, r := range s {
		// strip #'s and subscript digits
		if r < '₀' || '₀'+10 <= r { // '₀' == U+2080
			buf.WriteRune(r)
		}
	}
	if buf.Len() < len(s) {
		return buf.String()
	}
	return s