Rename __json__() to asdict()

tests/compute/virtualbox/test_virtualbox_vm.py

@@ -107,10 +107,10 @@ async def test_vm_adapter_add_nio_binding_adapter_not_exist(vm, manager, free_co
 
 def test_json(vm, tmpdir, project):
 
-    assert vm.__json__()["node_directory"] is None
+    assert vm.asdict()["node_directory"] is None
     project._path = str(tmpdir)
     vm._linked_clone = True
-    assert vm.__json__()["node_directory"] is not None
+    assert vm.asdict()["node_directory"] is not None
 
 
 def test_patch_vm_uuid(vm):