Define an attribute for the level element.
If a level element is defined as 'dynamic' by setting property 'levelType', you can add level attributes applied to it to filter some query result.
Name of the attribute.
This property gives out the name of the level attribute. A level attribute has a unique and required name.
Data type of the attribute.
This property gives out the data type of the level attribute. If you don't set the value, string is read as the default.