<project default="dont-run-this">
  <target name="dont-run-this">
    <fail>This build file is supposed to be run by a Unit test</fail>
  </target>

  <target name="testPropertyExpansion">
    <sequential>
      <property name="foo" value="it worked"/>
      <echo message="As attribute: ${foo}"/>
      <echo>As nested text: ${foo}</echo>
    </sequential>
  </target>
</project>