<xs:schema elementFormDefault='qualified' targetNamespace='http://example.org/echo' xmlns:tns='http://example.org/echo' xmlns:xs='http://www.w3.org/2001/XMLSchema'>
 <xs:element name='EchoInMessage'>
  <xs:complexType>
   <xs:sequence>
    <xs:element minOccurs='0' name='echoIn' nillable='true' type='xs:string'/>
   </xs:sequence>
  </xs:complexType>
 </xs:element>
 <xs:element name='EchoOutMessage'>
  <xs:complexType>
   <xs:sequence>
    <xs:element minOccurs='0' name='echoOut' nillable='true' type='xs:string'/>
   </xs:sequence>
  </xs:complexType>
 </xs:element>
</xs:schema>
