error: "Collection 'heroes' not found"

[HADDADENICAR]

I follow Angular'Http tutorial.
I have installed the 0.8.0 version of angular-in-memory-web-api,generated the service and added all the imports in app.module.

when i refresh the browser i got this error:

 [WDS] Disconnected! client:177
 Angular is running in the development mode. Call enableProdMode() to enable the production              mode. core.js:16829
   ERROR 
    {…}
body: Object { error: "Collection 'heroes' not found" }
headers: Object { normalizedNames: Map(0), lazyUpdate: null, lazyInit: lazyInit() }
status: 404
statusText: "Not Found"
url: "api/heroes"

[HADDADENICAR]

SOLVED ,instead of return{heroes} , i put return(heroes) and that triggered the issue .