code: function getEffectiveCommandValue(node, context) {
          var isElement = (node.nodeType == 1);
  
          // "If neither node nor its parent is an Element, return null."
          if (!isElement && (!node.parentNode || node.parentNode.nodeType != 1)) {
              return null;
          }
  
          // "If node is not an Element, return the effective command value of its parent for command."
          if (!isElement) {
              return getEffectiveCommandValue(node.parentNode, context);
          }
  
          return context.command.getEffectiveValue(node, context);
      }
docs: "effective value" per edit command spec