'Get all security groups associated with your account in a region.
:type groupnames: list
:param groupnames: A list of the names of security groups to retrieve.
If not provided, all security 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.rds.dbsecuritygroup.DBSecurityGroup`'

def get_all_dbsecurity_groups(self, groupname=None, max_records=None, marker=None):

    params = {}
    if groupname:
        params['DBSecurityGroupName'] = groupname
    if max_records:
        params['MaxRecords'] = max_records
    if marker:
        params['Marker'] = marker
    return self.get_list('DescribeDBSecurityGroups', params, [('DBSecurityGroup', DBSecurityGroup)])
