https://docs.oracle.com/javase/jp/7/api/javax/swing/plaf/synth/SynthRadioButtonUI.html
SynthRadioButtonUI (Java Platform SE 7)
java platformse
https://docs.oracle.com/javase/jp/18/docs/api/java.desktop/javax/swing/plaf/synth/SynthRadioButtonUI.html
SynthRadioButtonUI (Java SE 18 & JDK 18)
declaration: module: java.desktop, package: javax.swing.plaf.synth, class: SynthRadioButtonUI
java sejdk