docs: function isQuantifierNext(pattern, pos, flags) {
          return nativ.test.call(
              flags.indexOf('x') > -1 ?
                  // Ignore any leading whitespace, line comments, and inline comments
                  /^(?:\s+|#.*|\(\?#[^)]*\))*(?:[?*+]|{\d+(?:,\d*)?})/ :
                  // Ignore any leading inline comments
                  /^(?:\(\?#[^)]*\))*(?:[?*+]|{\d+(?:,\d*)?})/,
              pattern.slice(pos)
          );
      }