Angular – TS2416: Property ‘canActivate’ in type ‘MyGuard’ is not assignable to the same property in base type ‘CanActivate’

From the Spark Scala Programming guide's section on "Hadoop Datasets":

Spark can create distributed datasets from any file stored in the Hadoop distributed file system (HDFS) or other storage systems supported by Hadoop (including your local file system, Amazon S3, Hypertable, HBase, etc). Spark supports text files, SequenceFiles, and any other Hadoop InputFormat.

Support for gzip input files should work the same as it does in Hadoop. For example, sc.textFile("myFile.gz") should automatically decompress and read gzip-compressed files (textFile() is actually implemented using Hadoop's TextInputFormat, which supports gzip-compressed files).

As mentioned by @nick-chammas in the comments:

note that if you call sc.textFile() on a gzipped file, Spark will give you an RDD with only 1 partition (as of 0.9.0). This is because gzipped files are not splittable. If you don't repartition the RDD somehow, any operations on that RDD will be limited to a single core

Solved the issue with async / await and promise

The LoginService first import toPromise:

import 'rxjs/add/operator/toPromise';

Then created an async method in the LoginService

  async isAuthenticated(){
     const response = await this.http.get('/login/authenticated').toPromise();
     return response.json();
  }

Then in the component:

async canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
    this.loginStatus = await this.loginService.isAuthenticated();

    console.log("LOGGED IN STATUS: " + this.loginStatus);

    if (this.loginStatus == true){
        return true;
    }

    // not logged in so redirect to login page with the return url
    this.router.navigate(['/layout/login'], { queryParams: { returnUrl: state.url } });    
}