https://docs.oracle.com/javase/jp/6/api/javax/swing/plaf/basic/BasicRootPaneUI.html
BasicRootPaneUI (Java Platform SE 6)
java platformse
https://resources.mpi-inf.mpg.de/d5/teaching/ss05/is05/javadoc/javax/swing/plaf/basic/BasicRootPaneUI.html
BasicRootPaneUI