https://docs.oracle.com/javase/jp/8/docs/api/javax/swing/plaf/synth/SynthMenuBarUI.html
SynthMenuBarUI (Java Platform SE 8)
java platformse
https://docs.oracle.com/javase/jp/11/docs/api/java.desktop/javax/swing/plaf/synth/SynthMenuBarUI.html
SynthMenuBarUI (Java SE 11 & JDK 11 )
java sejdk