package ch.qos.logback.classic.pattern;
   
   import ch.qos.logback.classic.spi.ILoggingEvent;
   import ch.qos.logback.core.pattern.CompositeConverter;
   
   import static org.junit.jupiter.api.Assertions.assertNull;
   
   public class XCompositeConverter extends CompositeConverter<ILoggingEvent> {
   
      void assertNoNext() {
          assertNull( this.getNext(), "converter instance has next element");
      }
  
      @Override
      protected String transform(ILoggingEvent event, String in) {
          if (event.getMessage().contains("assert"))
              assertNoNext();
          return "";
      }
  
  }