Step of create model-XWorker

Editing model

Descriptor is aslo a structure, it's like schema, so we can use it generate a editor form to edit models.

Use xworker.lang.MetaDescriptor3 as descriptor to create new descriptor
Meta thing is special, because we use meta thing to create new descriptor. The most common meta thing is MetaDescriptor3.
Use new descriptor to create model
After you have your new descriptor, you can use it to write a specific model.