MavenSession session = legacySupport.getSession();

        PluginDescriptor pluginDescriptor;
        try {
            pluginDescriptor = pluginManager.getPluginDescriptor(
                    plugin, session.getCurrentProject().getRemotePluginRepositories(), session.getRepositorySession());

            pluginManager.setupPluginRealm(pluginDescriptor, session, null, null, null);
        } catch (Exception e) {

import org.apache.maven.api.plugin.descriptor.PluginDescriptor;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

/**
 * Verifies that subclasses from generated model classes are possible.
 */
class ExtendedPluginDescriptorTest {

    /**
     * A subclass of the generated class {@link PluginDescriptor} that adds an additional field.
     */