def list_resources(self, session, query='?*::INSTR'):
        """Returns a tuple of all connected devices matching query.

        :param query: regular expression used to match devices.
        """

        # For each session type, ask for the list of connected resources and merge them into a single list.

        resources = self.devices.list_resources()

        resources = rname.filter(resources, query)

        if resources:
            return resources

        raise errors.VisaIOError(errors.StatusCode.error_resource_not_found.value)
Returns a tuple of all connected devices matching query.

        :param query: regular expression used to match devices.