test/jaxp/javax/xml/jaxp/unittest/catalog/val_test.xsd

<?xml version="1.1"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
             targetNamespace="test">
     <xsd:element name="root">
         <xsd:complexType>
             <xsd:sequence>
                 <xsd:element name="child" type="xsd:anyType"/>
             </xsd:sequence>
         </xsd:complexType>

         <xsd:key name="key1">
             <xsd:selector xpath="."/>
             <xsd:field xpath="child"/>
         </xsd:key>
     </xsd:element>
</xsd:schema>