Support models with multi-level hierarchy (via roxspring) (#4503)

* Example of broken multi-level hierarchy

* Support for multiple levels of hierarchy in model objects

* Support for multiple levels of hierarchy in generators

* Regenerated samples

* Temporarily skip scalaz sample verification, which is having issue with Java version in CI container

* Re-enable scalaz in verify samples

Co-authored-by: Rob Oxspring <roxspring@imapmail.org>

samples/client/petstore/python-asyncio/test/test_big_cat.py

@@ -0,0 +1,39 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\  # noqa: E501
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by: https://openapi-generator.tech
+"""
+
+
+from __future__ import absolute_import
+
+import unittest
+
+import petstore_api
+from petstore_api.models.big_cat import BigCat  # noqa: E501
+from petstore_api.rest import ApiException
+
+
+class TestBigCat(unittest.TestCase):
+    """BigCat unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def testBigCat(self):
+        """Test BigCat"""
+        # FIXME: construct object with mandatory attributes with example values
+        # model = petstore_api.models.big_cat.BigCat()  # noqa: E501
+        pass
+
+
+if __name__ == '__main__':
+    unittest.main()

samples/client/petstore/python-asyncio/test/test_big_cat_all_of.py

@@ -0,0 +1,39 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\  # noqa: E501
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by: https://openapi-generator.tech
+"""
+
+
+from __future__ import absolute_import
+
+import unittest
+
+import petstore_api
+from petstore_api.models.big_cat_all_of import BigCatAllOf  # noqa: E501
+from petstore_api.rest import ApiException
+
+
+class TestBigCatAllOf(unittest.TestCase):
+    """BigCatAllOf unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def testBigCatAllOf(self):
+        """Test BigCatAllOf"""
+        # FIXME: construct object with mandatory attributes with example values
+        # model = petstore_api.models.big_cat_all_of.BigCatAllOf()  # noqa: E501
+        pass
+
+
+if __name__ == '__main__':
+    unittest.main()