Get list of image group resources from a SCO-API.

        Parameters
        ----------
        api_url : string, optional
            Base Url of the SCO-API. Uses default API if argument not present.
        offset : int, optional
            Starting offset for returned list items
        limit : int, optional
            Limit the number of items in the result
        properties : List(string)
            List of additional object properties to be included for items in
            the result

        Returns
        -------
        List(scoserv.ResourceHandle)
            List of resource handles (one per image group in the listing)

def image_groups_list(self, api_url=None, offset=0, limit=-1, properties=None):
        """Get list of image group resources from a SCO-API.

        Parameters
        ----------
        api_url : string, optional
            Base Url of the SCO-API. Uses default API if argument not present.
        offset : int, optional
            Starting offset for returned list items
        limit : int, optional
            Limit the number of items in the result
        properties : List(string)
            List of additional object properties to be included for items in
            the result

        Returns
        -------
        List(scoserv.ResourceHandle)
            List of resource handles (one per image group in the listing)
        """
        # Get subject listing Url for given SCO-API and return the retrieved
        # resource listing
        return sco.get_resource_listing(
            self.get_api_references(api_url)[sco.REF_IMAGE_GROUPS_LIST],
            offset,
            limit,
            properties
        )