Add tests for null variants

Author: Tarek Ahmed

constructorio-client/src/test/java/io/constructor/client/BrowseResponseTest.java

@@ -327,5 +327,9 @@ public void createBrowseResponseShouldReturnAResultWithFeatures() throws Excepti
                 "browse result feature variant [name] exists",
                 response.getResponse().getFeatures().get(0).getVariant().getName(),
                 "default_rules");
+        assertEquals(
+                "browse result feature variant returns null if empty",
+                response.getResponse().getFeatures().get(1).getVariant(),
+                null);
     }
 }

constructorio-client/src/test/java/io/constructor/client/SearchResponseTest.java

@@ -303,5 +303,9 @@ public void createSearchResponseShouldReturnAResultWithFeatures() throws Excepti
                 "search result feature variant [display name] exists",
                 response.getResponse().getFeatures().get(0).getVariant().getDisplayName(),
                 "Default weights");
+        assertEquals(
+                "search result feature variant returns null if empty",
+                response.getResponse().getFeatures().get(2).getVariant(),
+                null);
     }
 }