def _process_request(request)
      _error!(Errors::NotFoundError) unless request.valid?
      _validate_version(request)
      retval = _call_method(request)
      _response(request.post? ? 201 : 200, _prepare_response(retval))
    end
def _process_request(request)
      _error!(Errors::NotFoundError) unless request.valid?
      _validate_version(request)
      retval = _call_method(request)
      _response(request.post? ? 201 : 200, _prepare_response(retval))
    end
Validates the request, calls the appropriate Service::Resource method and
 returns a valid Rack response.