static extern libusb_device_handle libusb_open_device_with_vid_pid(libusb_context ctx, UInt16 vendor_id, UInt16 product_id);
static extern void libusb_set_debug(libusb_context ctx, int level);
public static extern ssize_t libusb_get_device_list(libusb_context ctx, out IntPtr *list); //libusb_device** list
public static extern int libusb_init(out libusb_context ctx);