def update_alias(FunctionName=None, Name=None, FunctionVersion=None,
    Description=None):
    """
    Using this API you can update the function version to which the alias points and the alias description. For more information, see Introduction to AWS Lambda Aliases .
    This requires permission for the lambda:UpdateAlias action.
    See also: AWS API Documentation
    
    Examples
    This operation updates a Lambda function alias
    Expected Output:
    
    :example: response = client.update_alias(
        FunctionName='string',
        Name='string',
        FunctionVersion='string',
        Description='string'
    )
    
    
    :type FunctionName: string
    :param FunctionName: [REQUIRED]
            The function name for which the alias is created. Note that the length constraint applies only to the ARN. If you specify only the function name, it is limited to 64 characters in length.
            

    :type Name: string
    :param Name: [REQUIRED]
            The alias name.
            

    :type FunctionVersion: string
    :param FunctionVersion: Using this parameter you can change the Lambda function version to which the alias points.

    :type Description: string
    :param Description: You can change the description of the alias using this parameter.

    :rtype: dict
    :return: {
        'AliasArn': 'string',
        'Name': 'string',
        'FunctionVersion': 'string',
        'Description': 'string'
    }
    
    
    """
    pass
