ANT_17_BRANCH/src/etc/testcases/taskdefs/toplevelsubant.xml

<?xml version="1.0"?>

<project name="ant-test" basedir="." default="bar">
  <subant target="foo">
    <fileset dir="." includes="toplevelsubant.xml"/>
  </subant>

  <target name="foo"/>
  <target name="bar"/>
</project>