<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:myns="http://myns"
           targetNamespace="http://myns"
           elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:element name="main_elt">
  <xs:complexType>
        <xs:sequence>
            <xs:element name="foo" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
  </xs:complexType>
</xs:element>

</xs:schema>