1 SealedTest01.java:19:43: compiler.err.cant.inherit.from.sealed: SealedTest01.SC
   2 SealedTest01.java:20:44: compiler.err.cant.inherit.from.sealed: SealedTest01.SAC
   3 SealedTest01.java:21:46: compiler.err.cant.inherit.from.sealed: SealedTest01.SI
   4 SealedTest01.java:22:47: compiler.err.cant.inherit.from.sealed: SealedTest01.SI
   5 4 errors