def start_schema_extension(DirectoryId=None,
    CreateSnapshotBeforeSchemaExtension=None, LdifContent=None, Description
    =None):
    """
    Applies a schema extension to a Microsoft AD directory.
    See also: AWS API Documentation
    
    
    :example: response = client.start_schema_extension(
        DirectoryId='string',
        CreateSnapshotBeforeSchemaExtension=True|False,
        LdifContent='string',
        Description='string'
    )
    
    
    :type DirectoryId: string
    :param DirectoryId: [REQUIRED]
            The identifier of the directory for which the schema extension will be applied to.
            

    :type CreateSnapshotBeforeSchemaExtension: boolean
    :param CreateSnapshotBeforeSchemaExtension: [REQUIRED]
            If true, creates a snapshot of the directory before applying the schema extension.
            

    :type LdifContent: string
    :param LdifContent: [REQUIRED]
            The LDIF file represented as a string. To construct the LdifContent string, precede each line as it would be formatted in an ldif file with n. See the example request below for more details. The file size can be no larger than 1MB.
            

    :type Description: string
    :param Description: [REQUIRED]
            A description of the schema extension.
            

    :rtype: dict
    :return: {
        'SchemaExtensionId': 'string'
    }
    
    
    """
    pass
