import java.util.*; import java.util.zip.*; import java.util.List; import java.util.regex.*; import java.util.concurrent.*; import java.util.concurrent.atomic.*; import java.util.concurrent.locks.*; import java.util.function.*; import javax.swing.*; import javax.swing.event.*; import javax.swing.text.*; import javax.swing.table.*; import java.io.*; import java.net.*; import java.lang.reflect.*; import java.lang.ref.*; import java.lang.management.*; import java.security.*; import java.security.spec.*; import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.awt.geom.*; import javax.imageio.*; import java.math.*; import java.time.Duration; import java.lang.invoke.VarHandle; import java.lang.invoke.MethodHandles; class main { static boolean syncClear_trueIfChanged(Collection c) { if (c == null) return false; synchronized(collectionMutex(c)) { if (c.isEmpty()) return false; c.clear(); return true; } } // TODO: JDK 17!! ?? No! Yes? Yes!! static Object collectionMutex(List l) { return l; } static Object collectionMutex(Object o) { if (o instanceof List) return o; // TODO: actually use our own maps so we can get the mutex properly String c = className(o); return o; } static String className(Object o) { return getClassName(o); } static String getClassName(Object o) { return o == null ? "null" : o instanceof Class ? ((Class) o).getName() : o.getClass().getName(); } }