<example2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:noNamespaceSchemaLocation="./example-2.xsd" >
	<!-- This is invalid according to the schema: the xs:choice
	 only allows one of <aaa> or <bbb> in the sequence, and not
			 both.  -->
	<xxx> string </xxx>
	<yyy> string </yyy>
	<aaa> string </aaa>
	<bbb> string </bbb>
</example2>

