 and of
            // non $1-9 pieces.
            const pieces = (label.match(/(\$[1-9])|(([^$]|\$([^1-9]|$))+)/g) ||
                            []).map(function(p) {
                // Pieces that are not $1-9 should be returned after replacing $$
                // with $.
                if (!p.match(/^\$[1-9]$/)) {
                    assert(
                        (p.match(/\$/g) || []).length % 2 === 0,
                        'Unescaped $ found in localized string.');
                    return {