Changed the way the union resolver matches an implementation.

Now its by name (if the name of the answer from the datafetcher is the same as one of the candidates)

Author: guy120494

src/main/java/graphql/annotations/typeResolvers/UnionTypeResolver.java

@@ -16,8 +16,9 @@
 
 import graphql.TypeResolutionEnvironment;
 import graphql.annotations.processor.ProcessingElementsContainer;
-import graphql.schema.*;
+import graphql.schema.GraphQLObjectType;
 import graphql.schema.GraphQLType;
+import graphql.schema.TypeResolver;
 
 import java.util.Arrays;
 import java.util.HashMap;
@@ -29,14 +30,16 @@ public class UnionTypeResolver implements TypeResolver {
 
     public UnionTypeResolver(Class<?>[] classes, ProcessingElementsContainer container) {
         Arrays.stream(classes).
-                forEach(c -> types.put(c,container.getDefaultTypeFunction().buildType(c, null, container)));
+                forEach(c -> types.put(c, container.getDefaultTypeFunction().buildType(c, null, container)));
     }
 
     @Override
     public GraphQLObjectType getType(TypeResolutionEnvironment env) {
         Object object = env.getObject();
-        Optional<Map.Entry<Class<?>, GraphQLType>> maybeType = types.entrySet().
-                stream().filter(e -> e.getKey().isAssignableFrom(object.getClass())).findFirst();
+        Optional<Map.Entry<Class<?>, GraphQLType>> maybeType = types.entrySet()
+                .stream().filter(e -> object.getClass().getSimpleName()
+                        .equals(e.getKey().getSimpleName())).findFirst();
+
         if (maybeType.isPresent()) {
             return (GraphQLObjectType) maybeType.get().getValue();
         } else {