Gets the {@link WSDLPort} that represents
the WSDL information about the port for which
a pipeline is created.
This model is present only when the client
provided WSDL to the JAX-WS runtime in some means
(such as indirectly through SEI or through {@link Dispatch}.)
JAX-WS allows modes of operations where no WSDL
is available for the current pipeline, and in which
case this model is not present.
return wsdlModel;