code: function isEqualRegexp(a, b) {
    if (typeOf(a) !== 'regexp') return false;
    if (typeOf(b) !== 'regexp') return false;
    if (a.source !== b.source) return false;
    if (a.global !== b.global) return false;
    if (a.multiline !== b.multiline) return false;
    if (a.ignoreCase !== b.ignoreCase) return false;
    return true;
  }
docs: Designed to exit early/fail fast when false.