regression introduced by 6594219: Plugin loads Swing classes

java.lang.NoSuchMethodError: java.lang.String.contains(Ljava/lang/CharSequence;)
Z
       at com.sun.deploy.util.DeployUIManager.getSystemLookAndFeelClassName(Unk
nown Source)
       at com.sun.deploy.util.DeployUIManager.setLookAndFeel(Unknown Source)
       at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
       at com.sun.javaws.Main$1.run(Unknown Source)
       at java.lang.Thread.run(Unknown Source)

Should not use String.contains in DeployUIManager.getSystemLookAndFeelClassName; String.contains only exists since 1.5