$this->portTypes[$bindingData['portType']][$operation]['output'] is undefined in One-way service

[galo4kin]

The service receives a message. The operation therefore has a single input element. The grammar for a one-way operation is −

<wsdl:definitions .... > 
   <wsdl:portType .... > *
      <wsdl:operation name = "nmtoken">
         <wsdl:input name = "nmtoken"? message = "qname"/>
      </wsdl:operation>
   </wsdl:portType >
</wsdl:definitions>

On this way we have an error in PHP8 on line 4930
$this->portTypes[$bindingData['portType']][$operation]['output']