<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
              elementFormDefault="qualified"
              attributeFormDefault="unqualified">

<xs:element name="main_elt">
  <xs:complexType>
    <xs:sequence>
        <xs:element name="foo" type="xs:string" minOccurs="1"/>
        <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>
