The `Paint` and `Material` classes can't be extended by user code, because their implementations require special support in internal JavaFX code. The classes should be sealed.
------------- Commit messages: - Seal Paint and Material Changes: https://git.openjdk.org/jfx/pull/1665/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1665&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8346227 Stats: 4 lines in 3 files changed: 1 ins; 0 del; 3 mod Patch: https://git.openjdk.org/jfx/pull/1665.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/1665/head:pull/1665 PR: https://git.openjdk.org/jfx/pull/1665
