<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _construct_stage(self, deployment, swagger):
 """Constructs and returns the ApiGateway Stage. :param model.apigateway.ApiGatewayDeployment deployment: the Deployment for this Stage :returns: the Stage to which this SAM Api corresponds :rtype: model.apigateway.ApiGatewayStage """


        # If StageName is some intrinsic function, then don't prefix the Stage's logical ID
        # This will NOT create duplicates because we allow only ONE stage per API resource
        stage_name_prefix = self.stage_name if isinstance(self.stage_name, string_types) else ""

        stage = ApiGatewayStage(self.logical_id + stage_name_prefix + 'Stage',
                                attributes=self.passthrough_resource_attributes)
        stage.RestApiId = ref(self.logical_id)
        stage.update_deployment_ref(deployment.logical_id)
        stage.StageName = self.stage_name
        stage.CacheClusterEnabled = self.cache_cluster_enabled
        stage.CacheClusterSize = self.cache_cluster_size
        stage.Variables = self.variables
        stage.MethodSettings = self.method_settings
        stage.AccessLogSetting = self.access_log_setting
        stage.CanarySetting = self.canary_setting
        stage.TracingEnabled = self.tracing_enabled

        if swagger is not None:
            deployment.make_auto_deployable(stage, swagger)

        return stage