Function start_native 

pub unsafe fn start_native(
    ns_window: *mut c_void,
    wk_webview: *mut c_void,
) -> Result<SessionReport, OffscreenError>

Start off-screen mode on a native window. macOS: ns_window is the NSWindow* and wk_webview the WKWebView*. Windows: ns_window carries the HWND value and wk_webview is ignored. Main thread only, before the window is first ordered.

Safety

Pointers must be live native objects for the duration of the session.