<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="reference"
           xmlns="reference" elementFormDefault="qualified">
    <xs:attribute name="name" type="xs:string"/>
    <xs:element name="class">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="student" type="xs:string" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:attribute ref="name"/>
        </xs:complexType>
    </xs:element>
</xs:schema>