title: Angular 2: Creating a Singelton class HTTP Service
body: <p>Currently I am Using <strong>HTTP Service</strong> in my Project , So I have to call the HTTP Services for every request, <strong>e.g</strong></p>
  
  <pre><code> this.http.get((`${this._getAPI}}`))
          .map(res =&gt; res.json())
          .catch(err =&gt; Observable.throw(err.json().error));
  }
  </code></pre>
  
  <p>that is working fine but have to write it for every request , what I want to is creating a Singleton Class for HTTP requests that have the functions to GET, POST, DELETE,EDIT , SO how can I achieve the Singelton Http Service class so i have no to write these line again for every request just want to have some like this</p>
  
  <pre><code>HttpService.callTheGetApi()//its just dummy example
  </code></pre>
  
  <p>where HttpService should be Singelton Class having single instance.</p>