Summary

Apply the sealed class modifer to java.awt.geom.Path2D

Problem

java.awt.geom.Path2D allows only two direct sub-classes : Path2D.Float and Path2D.Double but this is not as clear as it could be.

Solution

Use the new sealed class modifier to explicitly list the two allowed sub-classes. This is safe since there are no public or protected constructors for Path2D. However the sub-classes will need to be non-sealed since they do allow sub-classing.

Specification

java.awt.geom.Path2D

- public abstract class Path2D implements Shape, Cloneable 
+ public abstract sealed class Path2D implements Shape, Cloneable
+     permits Path2D.Double,
+             Path2D.Float   

-     public static class Float extends Path2D implements Serializable 
+     public static non-sealed class Float extends Path2D implements Serializable 

-     public static class Double extends Path2D implements Serializable 
+     public static non-sealed class Double extends Path2D implements Serializable