How to use the libusb1.get_iso_packet_list function in libusb1

# Returns whole buffers
        self.assertEqual(
            bytearray(itertools.chain(*transfer.getISOBufferList())),
            buff,
        )
        # Returns actually transfered data, so here nothing
        self.assertEqual(bytearray(
            itertools.chain(*[x for _, x in transfer.iterISO()])),
            bytearray(),
        )
        # Fake reception of whole transfers
        c_transfer = getattr(
          transfer,
          '_' + transfer.__class__.__name__ + '__transfer'
        )
        for iso_metadata in libusb1.get_iso_packet_list(c_transfer):
            iso_metadata.actual_length = iso_metadata.length
        # Now iterISO returns everythig
        self.assertEqual(bytearray(
            itertools.chain(*[x for _, x in transfer.iterISO()])),
            buff,
        )

raise ValueError('Too many ISO transfer lengths (%i), there are '
                'only %i ISO transfers available' % (configured_iso_packets,
                    num_iso_packets))
        if sum(iso_transfer_length_list) > buffer_length:
            raise ValueError('ISO transfers too long (%i), there are only '
                '%i bytes available' % (sum(iso_transfer_length_list),
                    buffer_length))
        transfer_p = self.__transfer
        self.__initialized = False
        self.__transfer_buffer = string_buffer
        self.__user_data = user_data
        libusb1.libusb_fill_iso_transfer(transfer_p, self.__handle,
            endpoint, string_buffer, buffer_length, configured_iso_packets,
            self.__ctypesCallbackWrapper, None, timeout)
        for length, iso_packet_desc in zip(iso_transfer_length_list,
                libusb1.get_iso_packet_list(transfer_p)):
            if length <= 0:
                raise ValueError('Negative/null length transfers are not '
                    'possible.')
            iso_packet_desc.length = length
        self.__callback = callback
        self.__initialized = True

'%i bytes available' % (
                    sum(iso_transfer_length_list),
                    buffer_length,
                )
            )
        transfer_p = self.__transfer
        self.__initialized = False
        self.__transfer_buffer = string_buffer
        self.__user_data = user_data
        libusb1.libusb_fill_iso_transfer(
            transfer_p, self.__handle, endpoint, string_buffer, buffer_length,
            configured_iso_packets, self.__ctypesCallbackWrapper, None,
            timeout)
        for length, iso_packet_desc in zip(
                iso_transfer_length_list,
                libusb1.get_iso_packet_list(transfer_p)):
            if length <= 0:
                raise ValueError(
                    'Negative/null length transfers are not possible.'
                )
            iso_packet_desc.length = length
        self.__callback = callback
        self.__initialized = True

- actual_length
        - status
        (see libusb1's API documentation for their signification)
        Should not be called on a submitted transfer (except for 'length'
        values).
        """
        transfer_p = self.__transfer
        transfer = transfer_p.contents
        if transfer.type != libusb1.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
            raise TypeError('This method cannot be called on non-iso '
                'transfers.')
        return [{
                'length': x.length,
                'actual_length': x.actual_length,
                'status': x.status,
            } for x in libusb1.get_iso_packet_list(transfer_p)]

- status
        (see libusb1's API documentation for their signification)
        Returned list is consistent with getISOBufferList return value.
        Should not be called on a submitted transfer (except for 'length'
        values).
        """
        transfer_p = self.__transfer
        transfer = transfer_p.contents
        if transfer.type != libusb1.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
            raise TypeError('This method cannot be called on non-iso '
                'transfers.')
        return [{
                'length': x.length,
                'actual_length': x.actual_length,
                'status': x.status,
            } for x in libusb1.get_iso_packet_list(transfer_p)]

configured_iso_packets = len(iso_transfer_length_list)
        if configured_iso_packets > num_iso_packets:
            raise ValueError('Too many ISO transfer lengths (%i), there are '
                'only %i ISO transfers available' % (configured_iso_packets,
                    num_iso_packets))
        if sum(iso_transfer_length_list) > buffer_length:
            raise ValueError('ISO transfers too long (%i), there are only '
                '%i bytes available' % (sum(iso_transfer_length_list),
                    buffer_length))
        transfer_p = self.__transfer
        self.__initialized = False
        libusb1.libusb_fill_iso_transfer(transfer_p, self.__handle,
            endpoint, string_buffer, buffer_length, num_iso_packets,
            self.__ctypesCallbackWrapper, user_data, timeout)
        for length, iso_packet_desc in zip(iso_transfer_length_list,
                libusb1.get_iso_packet_list(transfer_p)):
            if length <= 0:
                raise ValueError('Negative/null transfer length are not '
                    'possible.')
            iso_packet_desc.length = length
        self.__callback = callback
        self.__initialized = True

Generator yielding (status, buffer) for each isochornous transfer.
        buffer is truncated to actual_length.
        This is more efficient than calling both getISOBufferList and
        getISOSetupList when receiving data.
        Should not be called on a submitted transfer.
        """
        transfer_p = self.__transfer
        transfer = transfer_p.contents
        # pylint: disable=undefined-variable
        if transfer.type != TRANSFER_TYPE_ISOCHRONOUS:
            # pylint: enable=undefined-variable
            raise TypeError(
                'This method cannot be called on non-iso transfers.'
            )
        buffer_position = transfer.buffer
        for iso_transfer in libusb1.get_iso_packet_list(transfer_p):
            yield (
                iso_transfer.status,
                string_at(buffer_position, iso_transfer.actual_length),
            )
            buffer_position += iso_transfer.length

"""
        transfer_p = self.__transfer
        transfer = transfer_p.contents
        # pylint: disable=undefined-variable
        if transfer.type != TRANSFER_TYPE_ISOCHRONOUS:
            # pylint: enable=undefined-variable
            raise TypeError(
                'This method cannot be called on non-iso transfers.'
            )
        return [
            {
                'length': x.length,
                'actual_length': x.actual_length,
                'status': x.status,
            }
            for x in libusb1.get_iso_packet_list(transfer_p)
        ]