public static function fieldExists(FieldsCargo $cargo, string $name): bool
    {
        return array_key_exists($name, $cargo->fields);
    }
public static function fieldExists(FieldsCargo $cargo, string $name): bool
    {
        return array_key_exists($name, $cargo->fields);
    }
public static function fieldExists ( FieldsCargo $ cargo , string $ name ) : bool { return array_key_exists ( $ name , $ cargo -> fields ) ; }
Checks if there is such a field in the given particle.

Used by Get and Set.

@param FieldsCargo $cargo Fields cargo where we seek.
@param string $name Field name in question.

@return bool
Checks if there is such a field in the given particle .