<?xml version="1.0" encoding="ISO-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
	xmlns="http://FOO" targetNamespace="http://FOO">

	<xs:element name="foo">
		<xs:complexType>
			<xs:complexContent>
				<xs:extension base="typeA">										
					<xs:attribute name="barA_1" type="xs:string"  use="optional"/>					
					<xs:attribute name="barA_2" type="xs:string"  use="required"/>					
				</xs:extension>
			</xs:complexContent>
		</xs:complexType>
	</xs:element>

	<xs:complexType name="typeA">
		<xs:attribute name="barA_1" type="xs:string" use="required"/>				
	</xs:complexType>

</xs:schema>