XML Schema vallidate

Hello all!
I have a problem - hope anybody could help me
When I validate xml file using .xsd by Oracle xdk_java_9_0_1_0_0 I got folloving message:
(Error) Element 'output' not expected. 
..this is a part of .xsd ..
<complexType name="operationType">
<complexContent>
<extension base="documented">
<choice>
<group ref="one-way-operation"/>
<group ref="request-response-operation"/>
</choice>
<attribute name="name" type="AnyName" use="required"/>
</extension>
</complexContent>
</complexType>
<group name="one-way-operation">
<sequence>
<element ref="input"/>
</sequence>
</group>
<group name="request-response-operation">
<sequence>
<element ref="input"/>
<element ref="output"/>
<element ref="fault" minOccurs="0" maxOccurs="unbounded"/>
</sequence>
</group>
..
..here is part of XML..
<portType name="MyService">
<operation name="MyMethodName">
<input message="input"/>
<output message="output"/>
</operation>
</portType> 

How I understand, default value for choise is "one-way-operation"
When I change the plases line 1: and 2:
<choice>
1: <group ref="one-way-operation"/>
2: <group ref="request-response-operation"/>
</choice>
parser get me correct result.
In documenatation I not found descrition, how evidently set the choice...
Where is my mistake (how can I set value of choise by "request-response-operation" or parser not work correct (I think it is my error) :-( 

It is beforehand grateful