identityConstraint.xsd

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <!-- Test spaces in xs:key and xs:keyref 'name'
         and 'refer' attributes -->
    <xs:element name="root">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="referenced">
                    <xs:complexType>
                        <xs:attribute name="id" type="xs:string" />
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
        <xs:key name="aKey  ">
            <xs:selector xpath="root" />
            <xs:field xpath="@id" />
        </xs:key>
        <xs:keyref name="   aKeyRef   " refer="  aKey">
            <xs:selector xpath="referenced" />
            <xs:field xpath="@id" />
        </xs:keyref>
    </xs:element>
</xs:schema>