return document ? document.importNode(parsed, true) : parsed
    }

    def formatTree(Closure cl) {
        withCategories {
            return formatTree(cl.call())
        }
    }

    def withCategories(Closure cl) {
        use(BuildableDOMCategory) {
            return cl.call()
        }
    }

    def format(Node... nodes) {
        format(nodes as List)

                <section><title>Methods</title>
                    <table><thead><tr><td/></tr></thead></table>
                </section>
            </section>
        ''')

        when:
        ClassDoc doc = withCategories {
            def doc = new ClassDoc('org.gradle.Class', content, document, classMetaData, extensionMetaData)
            builder.build(doc)
            doc.mergeContent()
        }

        then:

            <tr><td>a</td></tr>
        </table>
    </section>
    <section><title>Methods</title><table><thead><tr></tr></thead></table></section>
</section>
''')

        when:
        ClassDoc doc = withCategories {
            def doc = new ClassDoc('org.gradle.Class', content, document, classMetaData, null)
            doc.superClass = superDoc
            doc.interfaces << superType1
            doc.interfaces << superType2

            <tr><td>b</td></tr>
        </table>
    </section>
    <section><title>Properties</title><table><thead><tr>Name</tr></thead></table></section>
</section>
''')

        when:
        ClassDoc doc = withCategories {
            def doc = new ClassDoc('org.gradle.Class', content, document, classMetaData, null)
            doc.superClass = superClass
            doc.interfaces << superType1
            doc.interfaces << superType2