Here is an example of how to use the Transform class from the logback library in Java:

import ch.qos.logback.core.pattern.transform.ClassicConverterTransformer;
import ch.qos.logback.core.pattern.transform.Transform;
import ch.qos.logback.core.pattern.util.RegularEscapeUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Example {
    private static final Logger logger = LoggerFactory.getLogger(Example.class);

    public static void main(String[] args) {
        String pattern = "%-5level %mdc{user} %msg%n";
        Transform<ILoggingEvent> transform = new ClassicConverterTransformer(pattern);
        String transformed = transform.transform(null);
        String escaped = RegularEscapeUtil.escape(transformed);
        logger.info("Transformed pattern: " + escaped);
    }
}

This example creates a Transform object and uses it to transform a pattern. The original pattern is given as a string, and the transform class is ClassicConverterTransformer, this class can be used to transform most of the conversion words used by logback. Then the transform() method is called on the Transform object, passing the original pattern as an argument.

This code will output the pattern in the format of :

Transformed pattern: %-5p %X{user} %m%n

Please note that

• You should import the relevant classes for logback
• The above code is just an example and it does not include the full context of a logging application.
• Since the the parameter passed is null, the method returns the tranformed string but not the transformed event
• You might want to use the transformed pattern in your logging configuration