Function gstreamer_rtsp_sys::gst_rtsp_connection_send_messages_usec

pub unsafe extern "C" fn gst_rtsp_connection_send_messages_usec(
    conn: *mut GstRTSPConnection, 
    messages: *mut GstRTSPMessage, 
    n_messages: c_uint, 
    timeout: i64
) -> GstRTSPResult

This is supported on crate feature v1_18 only.