Mapbox Provider prevents searching for countries

I'm using the Mapbox Provider in my API to fetch coordinates for given entities. These entities can be either:

• Countries
• Cities
• Districts
• Addresses

However, the current implementation of the mapbox provider prevents from returning anything that doesn't contain a context.

When I run this snippet and watch the console, I see that the query to Mapbox is correct and data is returned.
$locations = $mapboxGeocoder->geocodeQuery(
GeocodeQuery::create($country->getName())
->withLocale('nl')
->withData('location_type', 'country')
);

However, the fetchUrl method in Mapbox.php simply breaks when a result without context is returned by Mapbox.
https://github.com/geocoder-php/mapbox-provider/blob/master/Mapbox.php#L283

When I remove that piece of code, and add an additional check here to check if context is available before iterating through it, the code returns the requested items.
https://github.com/geocoder-php/mapbox-provider/blob/master/Mapbox.php#L301

This isn't a clean solution and additional models are required to make it a better implementation. However, the repo is read-only so I cannot help with the required changes

Review Mapbox.php around lines 283 and 301, starting with fetchUrl and the handling of Mapbox results without a context field. Trace the existing models used for context data and verify that country results are returned without breaking while cities, districts, and addresses retain their existing behavior.