#831 - Polishing.

Applied some recommendations provided by IntelliJ that I stumbled over while reviewing the changes.

src/main/java/org/springframework/hateoas/client/JsonPathLinkDiscoverer.java

@@ -166,7 +166,7 @@ public class JsonPathLinkDiscoverer implements LinkDiscoverer {
 			JSONArray jsonArray = (JSONArray) parseResult;
 
 			return jsonArray.stream() //
-					.flatMap(it -> JSONArray.class.isInstance(it) ? ((JSONArray) it).stream() : Stream.of(it)) //
+					.flatMap(it -> it instanceof JSONArray ? ((JSONArray) it).stream() : Stream.of(it)) //
 					.map(it -> extractLink(it, rel)) //
 					.collect(Collectors.collectingAndThen(Collectors.toList(), Links::of));
 		}

src/main/java/org/springframework/hateoas/client/Traverson.java

@@ -70,7 +70,7 @@ public class Traverson {
 				Traverson.class.getClassLoader());
 
 		Assert.isTrue(ALL_DEFAULTS.size() == 1,
-				() -> String.format("Expected to find only one TraversonDefaults instance, but found: ", //
+				() -> String.format("Expected to find only one TraversonDefaults instance, but found: %s", //
 						ALL_DEFAULTS.stream() //
 								.map(Object::getClass) //
 								.map(Class::getName) //