What happens if a module does not declare any `exports` in its `module-info.java` file?
If a module does not declare any `exports`, the module cannot be used by other modules in the application.
Thatâ€™s partially correct. The module can still be used internally within the application, but it wonâ€™t be accessible externally unless explicitly opened.
Can you explain what the `opens` keyword is used for and how it differs from `exports`?