title: Intercept Apollo/graphql requests
body: <p>we are using Apollo/Graphql in our application, and we are facing an issue.</p>
  
  <p>The application is developed in Angular 5, and NodeJS as backend with graphql server that will respond to the front end.
  To intercept Http request in angular, we implement the 'HttpInterceptor' so we can handle the errors in our customized way. But, Apollo request do not pass thru this intercepter. </p>
  
  <p>To handle the errors correctly, we are using 'apollo-link-error'.</p>
  
  <p>But we would like to know if it's possible to intercept apollo requests in a similar way as HttpInterceptor.</p>