'Returns a list of DBSubnetGroup descriptions. If a
DBSubnetGroupName is specified, the list will contain only the
descriptions of the specified DBSubnetGroup.
For an overview of CIDR ranges, go to the `Wikipedia
Tutorial`_.
:type db_subnet_group_name: string
:param db_subnet_group_name: The name of the DB subnet group to return
details for.
:type filters: list
:param filters:
:type max_records: integer
:param max_records: The maximum number of records to include in the
response. If more records exist than the specified `MaxRecords`
value, a pagination token called a marker is included in the
response so that the remaining results may be retrieved.
Default: 100
Constraints: minimum 20, maximum 100
:type marker: string
:param marker: An optional pagination token provided by a previous
DescribeDBSubnetGroups request. If this parameter is specified, the
response includes only records beyond the marker, up to the value
specified by `MaxRecords`.'

def describe_db_subnet_groups(self, db_subnet_group_name=None, filters=None, max_records=None, marker=None):

    params = {}
    if (db_subnet_group_name is not None):
        params['DBSubnetGroupName'] = db_subnet_group_name
    if (filters is not None):
        self.build_complex_list_params(params, filters, 'Filters.member', ('FilterName', 'FilterValue'))
    if (max_records is not None):
        params['MaxRecords'] = max_records
    if (marker is not None):
        params['Marker'] = marker
    return self._make_request(action='DescribeDBSubnetGroups', verb='POST', path='/', params=params)
