ValueError: The name 'admin' is already registered for a different blueprint. Use 'name=' to provide a unique name.

[chenfei5201213]

Traceback (most recent call last):
File "/Users/chenfei/anaconda3/bin/sandman2ctl", line 8, in
sys.exit(main())
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/sandman2/main.py", line 57, in main
app = get_app(args.URI, read_only=args.read_only, schema=args.schema)
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/sandman2/app.py", line 60, in get_app
_reflect_all(exclude_tables, admin, read_only, schema=schema)
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/sandman2/app.py", line 139, in _reflect_all
register_model(cls, admin)
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/sandman2/app.py", line 173, in register_model
admin.add_view(CustomAdminView(cls, db.session))
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/flask_admin/base.py", line 540, in add_view
self.app.register_blueprint(view.create_blueprint(self))
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/flask/scaffold.py", line 57, in wrapper_func
return f(self, *args, **kwargs)
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/flask/app.py", line 1028, in register_blueprint
blueprint.register(self, options)
File "/Users/chenfei/anaconda3/lib/python3.7/site-packages/flask/blueprints.py", line 306, in register
f"The name '{self_name}' is already registered for"
ValueError: The name 'admin' is already registered for a different blueprint. Use 'name=' to provide a unique name.