In your build.gradle (Module: app), you need to add the following dependency:

dependencies {
    //...
    compile 'com.google.android.gms:play-services:11.0.0'
}

and rebuild your app so it can download the needed dependencies. The class FusedLocationProviderClient is included in this package.

After getting location just remove mFusedLocationClient.removeLocationUpdates as he mentioned in above answers.

if (mFusedLocationClient != null) 
        mFusedLocationClient.removeLocationUpdates(mLocationCallback);

Looper will be called requestLocationUpdates until you remove it.

In my problem, I did as I mention above. Below is my code.

  mFusedLocationClient.getLastLocation()
                    .addOnSuccessListener(new OnSuccessListener<Location>() {
                        @Override
                        public void onSuccess(Location location) {
                            // GPS location can be null if GPS is switched off
                            if (location != null) {

                                mLocation = location;

                                if (mFusedLocationClient != null) {
                                    mFusedLocationClient.removeLocationUpdates(mLocationCallback);
                                }
                          } else {
                                startLocationUpdates();
                           }
                        }
                    })
                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            Toast.makeText(HomeActivity.this, "Error trying to get last GPS location", Toast.LENGTH_SHORT).show();
                            e.printStackTrace();
                        }
                    });

and below is my requestLocationUpdates so I will get a request until the location is available.

private void startLocationUpdates() {
        mSettingsClient.checkLocationSettings(mLocationSettingsRequest)
                .addOnSuccessListener(this, new OnSuccessListener<LocationSettingsResponse>() {
                    @Override
                    public void onSuccess(LocationSettingsResponse locationSettingsResponse) {
                        Log.i(TAG, "All location settings are satisfied.");

                        getPackageManager().checkPermission(Manifest.permission.ACCESS_FINE_LOCATION, getPackageName());
                        mFusedLocationClient.requestLocationUpdates(mLocationRequest,
                                mLocationCallback, Looper.myLooper());
                        getLastLocationNewMethod();
                    }
                })
                .addOnFailureListener(this, new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        int statusCode = ((ApiException) e).getStatusCode();
                        switch (statusCode) {
                            case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                                Log.i(TAG, "Location settings are not satisfied. Attempting to upgrade " +
                                        "location settings ");
                                try {
                                    ResolvableApiException rae = (ResolvableApiException) e;
                                    rae.startResolutionForResult(HomeActivity.this, 0x1);
                                } catch (IntentSender.SendIntentException sie) {
                                    Log.i(TAG, "PendingIntent unable to execute request.");
                                }
                                break;
                            case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                                String errorMessage = "Location settings are inadequate, and cannot be " +
                                        "fixed here. Fix in Settings.";
                                Log.e(TAG, errorMessage);
                                Toast.makeText(HomeActivity.this, errorMessage, Toast.LENGTH_LONG).show();
                                //  mRequestingLocationUpdates = false;
                        }
                        getLastLocationNewMethod();  // this method is where I can get location. It is calling above method. 
                    }
                });
    }

Note: For more information here is GitHub Repo LINK

Try adding @SuppressLint("MissingPermission") above the function.

@SuppressLint("MissingPermission")

Android Lint incorrectly reports missing location permission