def describe_db_security_groups(DBSecurityGroupName=None, Filters=None,
    MaxRecords=None, Marker=None):
    """
    Returns a list of DBSecurityGroup descriptions. If a DBSecurityGroupName is specified, the list will contain only the descriptions of the specified DB security group.
    See also: AWS API Documentation
    
    Examples
    This example lists settings for the specified security group.
    Expected Output:
    
    :example: response = client.describe_db_security_groups(
        DBSecurityGroupName='string',
        Filters=[
            {
                'Name': 'string',
                'Values': [
                    'string',
                ]
            },
        ],
        MaxRecords=123,
        Marker='string'
    )
    
    
    :type DBSecurityGroupName: string
    :param DBSecurityGroupName: The name of the DB security group to return details for.

    :type Filters: list
    :param Filters: This parameter is not currently supported.
            (dict) --This type is not currently supported.
            Name (string) -- [REQUIRED]This parameter is not currently supported.
            Values (list) -- [REQUIRED]This parameter is not currently supported.
            (string) --
            
            

    :type MaxRecords: integer
    :param MaxRecords: 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 can be retrieved.
            Default: 100
            Constraints: Minimum 20, maximum 100.
            

    :type Marker: string
    :param Marker: An optional pagination token provided by a previous DescribeDBSecurityGroups request. If this parameter is specified, the response includes only records beyond the marker, up to the value specified by MaxRecords .

    :rtype: dict
    :return: {
        'Marker': 'string',
        'DBSecurityGroups': [
            {
                'OwnerId': 'string',
                'DBSecurityGroupName': 'string',
                'DBSecurityGroupDescription': 'string',
                'VpcId': 'string',
                'EC2SecurityGroups': [
                    {
                        'Status': 'string',
                        'EC2SecurityGroupName': 'string',
                        'EC2SecurityGroupId': 'string',
                        'EC2SecurityGroupOwnerId': 'string'
                    },
                ],
                'IPRanges': [
                    {
                        'Status': 'string',
                        'CIDRIP': 'string'
                    },
                ],
                'DBSecurityGroupArn': 'string'
            },
        ]
    }
    
    
    :returns: 
    DescribeDBSecurityGroups
    AuthorizeDBSecurityGroupIngress
    CreateDBSecurityGroup
    RevokeDBSecurityGroupIngress
    
    """
    pass
