use libnghttp2::*;

let mut callbacks = std::ptr::null_mut();
nghttp2_session_callbacks_new(&mut callbacks);
nghttp2_session_callbacks_set_send_callback(callbacks, Some(send_cb));
nghttp2_session_callbacks_set_on_frame_recv_callback(callbacks, Some(frame_recv_cb));
nghttp2_session_callbacks_set_on_data_chunk_recv_callback(callbacks, Some(data_cb));

let mut session_ptr = ptr::null_mut();
nghttp2_session_client_new(&mut session_ptr, callbacks, user_data);

// Submit HTTP/2 request
let headers = [
  nghttp2_nv { name: b":method\0".as_ptr() as *mut u8, value: b"GET\0".as_ptr() as *mut u8, /* ... */ },
  nghttp2_nv { name: b":scheme\0".as_ptr() as *mut u8, value: b"http\0".as_ptr() as *mut u8, /* ... */ },
  // ...
];
nghttp2_submit_request(session_ptr, ptr::null(), headers.as_ptr(), headers.len(), ptr::null(), ptr::null_mut());