<?xml version="1.0"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:t="test" targetNamespace="test">

  <!-- Multiple levels of forward reference. -->

  <complexType name="type">
    <attributeGroup ref="t:g1"/>
  </complexType>

  <attributeGroup name="g1">
    <attributeGroup ref="t:g2"/>
    <attributeGroup ref="t:g3"/>
  </attributeGroup>

  <attributeGroup name="g2">
    <attribute ref="t:foo2"/>
    <attribute ref="t:bar2" use="required"/>
  </attributeGroup>

  <attributeGroup name="g3">
    <attribute ref="t:foo3"/>
    <attribute ref="t:bar3" use="required"/>
  </attributeGroup>

  <attribute name="foo2" type="string"/>
  <attribute name="bar2" type="string"/>

  <attribute name="foo3" type="string"/>
  <attribute name="bar3" type="string"/>

</schema>
