CONSOLE MESSAGE: line 10: CustomEvent received in main world
CONSOLE MESSAGE: line 11: detail was {"foo":5,"bar":"hello","targetWorld":"main"}
CONSOLE MESSAGE: line 3: CustomEvent received in isolated world
CONSOLE MESSAGE: line 4: detail was {"foo":5,"bar":"hello","targetWorld":"isolated"}
Tests that properties of CustomEvent initialized with initCustomEvent() are cloned when accessed in isolated worlds.