code: function(selector) {
      for (var ii = 0; ii < document.styleSheets.length; ++ii) {
        var styleSheet = document.styleSheets[ii];
        var rules = styleSheet.cssRules || styleSheet.rules;
        if (rules) {
          for (var rr = 0; rr < rules.length; ++rr) {
            var rule = rules[rr];
            if (rule.selectorText === selector) {
              return rule;
            }
          }
        }
      }
    }
docs: finds a CSS rule.
  @param {string} selector
  @return {Rule?} matching css rule
  @memberOf module:Misc