Tests: note why to rely on tests or the library to clean up resources

Author: greenrobot-team

tests/objectbox-java-test/src/test/java/io/objectbox/AbstractObjectBoxTest.java

@@ -162,6 +162,10 @@ protected Box<TestEntity> getTestEntityBox() {
 
     @After
     public void tearDown() {
+        // Note: do not collect dangling Cursors and Transactions before store closes (using System.gc()
+        // or System.runFinalization()). Tests should mirror user code and do that themselves (calling close())
+        // or rely on the library (through finalizers or BoxStore.close()).
+
         if (store != null) {
             try {
                 store.close();