public static function continents() : Collection
    {
        $file = __DIR__ . "/../Assets/topojson/world-continents.json";

        return Collection::make(
            json_decode(file_get_contents($file), true)['objects']['continent']['geometries']
        )->map(function ($continent) {
            return $continent['properties']['continent'];
        });
    }
public static function continents() : Collection
    {
        $file = __DIR__ . "/../Assets/topojson/world-continents.json";

        return Collection::make(
            json_decode(file_get_contents($file), true)['objects']['continent']['geometries']
        )->map(function ($continent) {
            return $continent['properties']['continent'];
        });
    }
public static function continents ( ) : Collection { $ file = __DIR__ . "/../Assets/topojson/world-continents.json" ; return Collection :: make ( json_decode ( file_get_contents ( $ file ) , true ) [ 'objects' ] [ 'continent' ] [ 'geometries' ] ) -> map ( function ( $ continent ) { return $ continent [ 'properties' ] [ 'continent' ] ; } ) ; }
Return the world continents.

@author Erik Campobadal Fores <soc@erik.cat>
@copyright 2017 erik.cat
@return Collection
Return the world continents .