}
    }

    private void addTaskDefinition(String name, String className) throws ClassNotFoundException {
        DynamicObject project = DynamicObjectUtil.asDynamicObject(builder.getProperty("project"));
        project.invokeMethod("addTaskDefinition", name, antlibClassLoader.loadClass(className));
    }

    public Object propertyMissing(String name) {

    static def assertSetContains(FileCollection set, Set<String> filenames, Iterable<FileCollection.AntType> types, boolean generic = true) {
        AntBuilder ant = new DefaultAntBuilder(null, null)
        ant.antProject.addTaskDefinition('test', FileListTask)

        if (generic) {
            FileListTask task = ant.test {
                set.addToAntBuilder(ant, null)
            }
            assertThat(task.filenames, equalTo(filenames))