private HttpResponse resume(RestApi.RequestContext context) {
        String applicationIdString = context.pathParameters().getStringOrThrow("application");
        ApplicationId applicationId = toApplicationId(applicationIdString);
        try {
            orchestrator.resume(applicationId);
        } catch (ApplicationIdNotFoundException e) {
            log.log(Level.INFO, "ApplicationId " + applicationIdString + " not found.", e);
            throw new RestApiException.NotFound(e);
        } catch (ApplicationStateChangeDeniedException e) {
            log.log(Level.INFO, "Suspend for " + applicationIdString + " failed.", e);
            throw new RestApiException.Conflict();
        } catch (RuntimeException e) {
            log.log(Level.INFO, "Suspend for " + applicationIdString + " failed from unknown reasons", e);
            throw new RestApiException.InternalServerError(e);
        }
        return new EmptyResponse(Status.NO_CONTENT);
    }
Resume normal operations for all services for an application
instance that has previously been allowed suspension.

If the host is already registered as running normal operations, then resume() is idempotent
and will succeed.

HTTP Behavior:
Returns 204 is the resume operation was successful (or the application was not suspended)
Returns 400 if the applicationId is invalid
orchestrator/src/main/java/com/yahoo/vespa/orchestrator/resources/ApplicationSuspensionRequestHandler.java