Rebased to current upstream/master. (#4514)

Tests for python client, comprising support for additional_properties and arrays.
There are ugly workarounds for when there are discriminators, since the python client generator does not fully handle them.
Cool indentation of test files.

samples/client/petstore/python/test/test_animal.py

@@ -5,7 +5,7 @@
 
     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
 
-    OpenAPI spec version: 1.0.0
+    The version of the OpenAPI document: 1.0.0
     Generated by: https://openapi-generator.tech
 """
 
@@ -13,12 +13,12 @@
 from __future__ import absolute_import
 
 import unittest
+import datetime
 
 import petstore_api
 from petstore_api.models.animal import Animal  # noqa: E501
 from petstore_api.rest import ApiException
 
-
 class TestAnimal(unittest.TestCase):
     """Animal unit test stubs"""
 
@@ -28,11 +28,26 @@ class TestAnimal(unittest.TestCase):
     def tearDown(self):
         pass
 
+    def make_instance(self, include_optional):
+        """Test Animal
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # model = petstore_api.models.animal.Animal()  # noqa: E501
+        if include_optional :
+            return Animal(
+                class_name = '0', 
+                color = 'red'
+            )
+        else :
+            return Animal(
+                class_name = '0',
+        )
+
     def testAnimal(self):
         """Test Animal"""
-        # FIXME: construct object with mandatory attributes with example values
-        # model = petstore_api.models.animal.Animal()  # noqa: E501
-        pass
+        inst_req_only = self.make_instance(include_optional=False)
+        inst_req_and_optional = self.make_instance(include_optional=True)
 
 
 if __name__ == '__main__':