Some applications have used core reflection to instantiate JDK internal Swing L&Fs,
i.e system L&Fs such as The Windows L&F :
`Class.forName(" com.sun.java.swing.plaf.windows.WindowsLookAndFeel")`

These classes are internal to the JDK and applications should have always treated them as such.

As of JDK 9 whether these are accessible to applications depends on the configuration
of the Java Platform Module System and the value of the --illegal-access setting.
By default in JDK 9 its value is "permit", but this is expected to change to "deny"
in a future release.

Applications which need to create a system L&F must migrate to use the new method :
`javax.swing.UIManager.createLookAndFeel(String name)`.