code: 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)
          );
      }
docs: Checks whether the next nonignorable token after the specified position is a quantifier.
  
  @private
  @param {String} pattern Pattern to search within.
  @param {Number} pos Index in `pattern` to search at.
  @param {String} flags Flags used by the pattern.
  @returns {Boolean} Whether the next token is a quantifier.