code: def findStyleFor(self, element, attrName, default=NotImplemented):
          
          rule = self.findCSSRulesFor(element, attrName)
          return self._extractStyleForRule(rule, attrName, default)
docs: Attempts to find the style setting for attrName in the CSSRulesets.
  
          Note: This method does not attempt to resolve rules that return
          "inherited", "default", or values that have units (including "%").
          This is left up to the client app to re-query the CSS in order to
          implement these semantics.