Here is an example of a class using NodeToStringTransformer in Logback:

import ch.qos.logback.core.joran.spi.ElementPath;
import ch.qos.logback.core.joran.spi.Node;
import ch.qos.logback.core.joran.util.ConfigurationWatchListUtil;
import ch.qos.logback.core.joran.util.NodeToStringTransformer;

public class MyClass {

    public void doSomething() {
        ElementPath elementPath = new ElementPath("configuration");
        Node node = ConfigurationWatchListUtil.getConfigurationWatchList().getConfiguration();
        String xmlString = NodeToStringTransformer.nodeToString(node);
    }
}

This class is an example of using NodeToStringTransformer in Logback. NodeToStringTransformer is a utility class that provides a method nodeToString(Node node) which is used to convert a Node object to a string representation of its XML.

In this example, MyClass has a doSomething method, which creates a ElementPath object, and retrieves the Node object of the configuration file by calling ConfigurationWatchListUtil.getConfigurationWatchList().getConfiguration(), then it creates a string representation of the configuration file by calling NodeToStringTransformer.nodeToString(node).

It is important to note that NodeToStringTransformer is a utility class that provides a way to convert a Node object to a string representation of its XML. The Node object represents an element in an XML configuration file and it is part of the Joran configuration framework used by Logback. The NodeToStringTransformer class can be used to programmatically convert a Node object to a string representation of its XML, which can be useful for debugging or for saving the configuration to a file.