code: def test_nested_property_set(self):
      Json = self.classes.Json
  
      j = Json()
      j.subfield = "a"
      eq_(j.json, {"other": {"field": "a"}})
  
imports: import sqlalchemy
  from sqlalchemy import inspect
  from sqlalchemy import Integer
  from sqlalchemy import testing
  from sqlalchemy import Text
  from sqlalchemy.ext.indexable import index_property
  from sqlalchemy.orm import declarative_base
  from sqlalchemy.orm import Session
  from sqlalchemy.sql.sqltypes import ARRAY
  from sqlalchemy.sql.sqltypes import JSON
  from sqlalchemy.testing import assert_raises
  from sqlalchemy.testing import eq_
  from sqlalchemy.testing import fixtures
  from sqlalchemy.testing import in_
  from sqlalchemy.testing import is_
  from sqlalchemy.testing import ne_
  from sqlalchemy.testing import not_in
  from sqlalchemy.testing.entities import ComparableEntity
  from sqlalchemy.testing.schema import Column
label_desc: Use image node_id 8 for calling the IndexPropertyJsonTest obj's underlying member method code with example usage: obj.test_nested_property_set() without return types