code: public static PropertyNode getStaticProperty(ClassNode cNode, String propName) {
          ClassNode classNode = cNode;
          while (classNode != null) {
              for (PropertyNode pn : classNode.getProperties()) {
                  if (pn.getName().equals(propName) && pn.isStatic()) return pn;
              }
              classNode = classNode.getSuperClass();
          }
          return null;
      }
docs: Detect whether a static property with the given name is within the class
  or a super class.
  
  @param cNode the ClassNode of interest
  @param propName the property name
  @return the static property if found or else null