code: function (selectorText) {
              var rule, css, selector, cssRules = this.cssRules;
              if (selectorText) {
                  rule = cssRules[selectorText];
                  return rule ? rule.style.cssText : null;
              } else {
                  css = [];
                  for (selector in cssRules) {
                      rule = cssRules[selector];
                      css.push(rule.selectorText + ' {' + rule.style.cssText + '}');
                  }
                  return css.join('\n');
              }
          }
docs: Get cssText corresponding to specified selectorText
  @param {String} selectorText specified selector as string
  @return {String} CssText corresponding to specified selectorText