inbound.go
func (response *InboundCallResponse) SetApplicationError() error {
	if response.state > reqResWriterPreArg2 {
		return response.failed(errReqResWriterStateMismatch{
			state:         response.state,
			expectedState: reqResWriterPreArg2,
		})
	}
	response.applicationError = true
	return nil
}
func (response *InboundCallResponse) SetApplicationError() error {
	if response.state > reqResWriterPreArg2 {
		return response.failed(errReqResWriterStateMismatch{
			state:         response.state,
			expectedState: reqResWriterPreArg2,
		})
	}
	response.applicationError = true
	return nil
}
// SetApplicationError marks the response as being an application error.  This method can
// only be called before any arguments have been sent to the calling peer.