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/java/feign/src/test/java/org/openapitools/client/model/BigCatAllOfTest.java

@@ -0,0 +1,49 @@
+/*
+ * 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: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for BigCatAllOf
+ */
+public class BigCatAllOfTest {
+    private final BigCatAllOf model = new BigCatAllOf();
+
+    /**
+     * Model tests for BigCatAllOf
+     */
+    @Test
+    public void testBigCatAllOf() {
+        // TODO: test BigCatAllOf
+    }
+
+    /**
+     * Test the property 'kind'
+     */
+    @Test
+    public void kindTest() {
+        // TODO: test kind
+    }
+
+}

samples/client/petstore/java/feign/src/test/java/org/openapitools/client/model/BigCatTest.java

@@ -0,0 +1,75 @@
+/*
+ * 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: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.model;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+import org.openapitools.client.model.BigCatAllOf;
+import org.openapitools.client.model.Cat;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for BigCat
+ */
+public class BigCatTest {
+    private final BigCat model = new BigCat();
+
+    /**
+     * Model tests for BigCat
+     */
+    @Test
+    public void testBigCat() {
+        // TODO: test BigCat
+    }
+
+    /**
+     * Test the property 'className'
+     */
+    @Test
+    public void classNameTest() {
+        // TODO: test className
+    }
+
+    /**
+     * Test the property 'color'
+     */
+    @Test
+    public void colorTest() {
+        // TODO: test color
+    }
+
+    /**
+     * Test the property 'declawed'
+     */
+    @Test
+    public void declawedTest() {
+        // TODO: test declawed
+    }
+
+    /**
+     * Test the property 'kind'
+     */
+    @Test
+    public void kindTest() {
+        // TODO: test kind
+    }
+
+}