Add tests for anyof with discriminator (#19021)

* add tests for anyof with discriminator

* remove test

* update samples

samples/openapi3/client/petstore/java/jersey2-java8/docs/MammalAnyof.md

@@ -0,0 +1,46 @@
+
+
+# MammalAnyof
+
+## anyOf schemas
+* [Pig](Pig.md)
+* [Whale](Whale.md)
+* [Zebra](Zebra.md)
+
+## Example
+```java
+// Import classes:
+import org.openapitools.client.model.MammalAnyof;
+import org.openapitools.client.model.Pig;
+import org.openapitools.client.model.Whale;
+import org.openapitools.client.model.Zebra;
+
+public class Example {
+    public static void main(String[] args) {
+        MammalAnyof exampleMammalAnyof = new MammalAnyof();
+
+        // create a new Pig
+        Pig examplePig = new Pig();
+        // set MammalAnyof to Pig
+        exampleMammalAnyof.setActualInstance(examplePig);
+        // to get back the Pig set earlier
+        Pig testPig = (Pig) exampleMammalAnyof.getActualInstance();
+
+        // create a new Whale
+        Whale exampleWhale = new Whale();
+        // set MammalAnyof to Whale
+        exampleMammalAnyof.setActualInstance(exampleWhale);
+        // to get back the Whale set earlier
+        Whale testWhale = (Whale) exampleMammalAnyof.getActualInstance();
+
+        // create a new Zebra
+        Zebra exampleZebra = new Zebra();
+        // set MammalAnyof to Zebra
+        exampleMammalAnyof.setActualInstance(exampleZebra);
+        // to get back the Zebra set earlier
+        Zebra testZebra = (Zebra) exampleMammalAnyof.getActualInstance();
+    }
+}
+```
+
+