code: private static boolean isAttributeAllowed(Schema property) {
  
          if (property.getType() == SchemaType.ARRAY || property.getType() == SchemaType.OBJECT) {
              return false;
          }
  
          if (!StringUtils.isBlank(property.getRef())) {
              return false;
          }
          return true;
      }
docs: Checks whether the passed property can be represented as node attribute.
  
  @param property property instance to be checked
  @return <code>true</code> if the passed property can be represented as
  node attribute