def get_supported_interfaces(handler_input):
    """Retrieves the supported interfaces from input request.

    The method returns an
    :py:class:`ask_sdk_model.supported_interfaces.SupportedInterfaces`
    object instance listing each interface that the device
    supports. For example, if ``supported_interfaces`` includes
    ``audio_player``, then you know that the device supports streaming
    audio using the AudioPlayer interface. More information on
    `supportedInterfaces` can be found here :
    https://developer.amazon.com/docs/custom-skills/request-and-response-json-reference.html#system-object

    :param handler_input: The handler input instance that is generally
        passed in the sdk's request and exception components
    :type handler_input: ask_sdk_core.handler_input.HandlerInput
    :return: Instance of
        :py:class:`ask_sdk_model.supported_interfaces.SupportedInterfaces`
        mentioning which all interfaces the device supports
    :rtype: ask_sdk_model.supported_interfaces.SupportedInterfaces
    """
    return (handler_input.request_envelope.context.system.device.
        supported_interfaces)
