DslReference dslReference = extension.getDslReference();

        TaskProvider<ExtractDslMetaDataTask> dslMetaData = tasks.register("dslMetaData", ExtractDslMetaDataTask.class, task -> {
            task.source(extension.getDocumentedSource());
            task.getDestinationFile().convention(dslReference.getStagingRoot().file("dsl-meta-data.bin"));

import org.w3c.dom.Element
/**
 * Generates the docbook source for the DSL reference guide.
 *
 * Uses the following as input:
 * <ul>
 * <li>Meta-data extracted from the source by {@link gradlebuild.docs.dsl.source.ExtractDslMetaDataTask}.</li>
 * <li>Meta-data about the plugins, in the form of an XML file.</li>
 * <li>{@code sourceFile} - A main docbook template file containing the introductory material and a list of classes to document.</li>