Java: refactor QL

java/ql/lib/semmle/code/java/UnitTests.qll

@@ -112,6 +112,14 @@ class JUnitJupiterTestMethod extends Method {
   }
 }
 
+/**
+ * A JUnit test class that contains at least one method annotated with
+ * `org.junit.jupiter.api.Test`.
+ */
+class JUnit5TestClass extends Class {
+  JUnit5TestClass() { this.getAMethod() instanceof JUnitJupiterTestMethod }
+}
+
 /**
  * A JUnit `@Ignore` annotation.
  */