'Returns a list of the available DB engines.
:type engine: string
:param engine: The database engine to return.
:type engine_version: string
:param engine_version: The database engine version to return.
Example: `5.1.49`
:type db_parameter_group_family: string
:param db_parameter_group_family:
The name of a specific DB parameter group family to return details for.
Constraints:
+ Must be 1 to 255 alphanumeric characters
+ First character must be a letter
+ Cannot end with a hyphen or contain two consecutive hyphens
:type max_records: integer
:param max_records: The maximum number of records to include in the
response. If more than the `MaxRecords` value is available, a
pagination token called a marker is included in the response so
that the following results can be retrieved.
Default: 100
Constraints: minimum 20, maximum 100
:type marker: string
:param marker: An optional pagination token provided by a previous
request. If this parameter is specified, the response includes only
records beyond the marker, up to the value specified by
`MaxRecords`.
:type default_only: boolean
:param default_only: Indicates that only the default version of the
specified engine or engine and major version combination is
returned.
:type list_supported_character_sets: boolean
:param list_supported_character_sets: If this parameter is specified,
and if the requested engine supports the CharacterSetName parameter
for CreateDBInstance, the response includes a list of supported
character sets for each engine version.'

def describe_db_engine_versions(self, engine=None, engine_version=None, db_parameter_group_family=None, max_records=None, marker=None, default_only=None, list_supported_character_sets=None):

    params = {}
    if (engine is not None):
        params['Engine'] = engine
    if (engine_version is not None):
        params['EngineVersion'] = engine_version
    if (db_parameter_group_family is not None):
        params['DBParameterGroupFamily'] = db_parameter_group_family
    if (max_records is not None):
        params['MaxRecords'] = max_records
    if (marker is not None):
        params['Marker'] = marker
    if (default_only is not None):
        params['DefaultOnly'] = str(default_only).lower()
    if (list_supported_character_sets is not None):
        params['ListSupportedCharacterSets'] = str(list_supported_character_sets).lower()
    return self._make_request(action='DescribeDBEngineVersions', verb='POST', path='/', params=params)
