public static extern void cdo_stop_measuring_stats(cdo_void_rclbck_t rclbck, CDOH handle, 
     IntPtr opaque, ref CDOString scopeId);
 public static extern void cdo_unpublish(cdo_void_rclbck_t rclbck,
     CDOH handle, IntPtr opaque, ref CDOString scopeId,
     ref CDOString what);
 public static extern void cdo_set_audio_output_device(
     cdo_void_rclbck_t rclbck, CDOH handle, IntPtr opaque,
     ref CDOString device_id);
 public static extern void cdo_set_video_capture_device(
     cdo_void_rclbck_t rclbck, CDOH handle, IntPtr opaque,
     ref CDOString device_id);
 public static extern void cdo_send_message(cdo_void_rclbck_t rclbck,
     CDOH handle, IntPtr opaque, ref CDOString scopeId,
     [MarshalAs(UnmanagedType.LPStr)]string msgBody,
     UIntPtr msgSize, ref Int64 recipientId);
 public static extern void cdo_send_echo_notification(
     cdo_void_rclbck_t resultHandler, CDOH handle, IntPtr opaque,
     ref CDOString content);
 public static extern void cdo_publish(cdo_void_rclbck_t rclbck,
     CDOH handle, IntPtr opaque, ref CDOString scopeId,
     ref CDOString what, ref CDOMediaPublishOptions options);
 public static extern void cdo_disconnect(cdo_void_rclbck_t rclbck,
     CDOH handle, IntPtr opaque, ref CDOString scopeId);
 public static extern void cdo_connect_string(cdo_void_rclbck_t rclbck,
     CDOH handle, IntPtr opaque, ref CDOString connDescr);