def get_all_dbparameter_groups(self, groupname=None, max_records=None,
                                  marker=None):
        """
        Get all parameter groups associated with your account in a region.

        :type groupname: str
        :param groupname: The name of the DBParameter group to retrieve.
                          If not provided, all DBParameter groups will be returned.

        :type max_records: int
        :param max_records: The maximum number of records to be returned.
                            If more results are available, a MoreToken will
                            be returned in the response that can be used to
                            retrieve additional records.  Default is 100.

        :type marker: str
        :param marker: The marker provided by a previous request.

        :rtype: list
        :return: A list of :class:`boto.ec2.parametergroup.ParameterGroup`
        """
        params = {}
        if groupname:
            params['DBParameterGroupName'] = groupname
        if max_records:
            params['MaxRecords'] = max_records
        if marker:
            params['Marker'] = marker
        return self.get_list('DescribeDBParameterGroups', params,
                             [('DBParameterGroup', ParameterGroup)])