def get_containers(self, include_only=[]):
        """Download all the containers owned by a group

        Arguments
        ---------
        include_only: List containg `Group` or `Location` objects
            Search only over a list of groups or locations         
        """
        locations = self.get_locations() 
        if len(locations) == 0:
            raise ValueError("No locations for containers exist in Cheminventory")

        final_locations = []
        if include_only:
            for location in locations:
                check = location in include_only or location.group in include_only
                if check:
                    final_locations.append(location)
            if len(final_locations)==0: raise ValueError(f"Location(s) or group(s) {include_only} is/are not in the database.")
        else:
            final_locations = locations

        containers = []
        for location in final_locations:
            containers += self._get_location_containers(location.inventory_id)

        return containers