* otherwise a negative error value
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @post webrtc_peer_connection_state_change_cb() will be invoked.
* @see webrtc_unset_peer_connection_state_change_cb()
* @see webrtc_peer_connection_state_change_cb()
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
* @retval #WEBRTC_ERROR_INVALID_OPERATION Invalid operation
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @see webrtc_set_peer_connection_state_change_cb()
* @see webrtc_get_peer_connection_state()
*/
* otherwise a negative error value
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @post webrtc_signaling_state_change_cb() will be invoked.
* @see webrtc_unset_signaling_state_change_cb()
* @see webrtc_signaling_state_change_cb()
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
* @retval #WEBRTC_ERROR_INVALID_OPERATION Invalid operation
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @see webrtc_set_signaling_state_change_cb()
* @see webrtc_get_signaling_state()
*/
* otherwise a negative error value
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @post webrtc_ice_gathering_state_change_cb() will be invoked.
* @see webrtc_unset_ice_gathering_state_change_cb()
* @see webrtc_ice_gathering_state_change_cb()
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
* @retval #WEBRTC_ERROR_INVALID_OPERATION Invalid operation
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @see webrtc_set_ice_gathering_state_change_cb()
* @see webrtc_get_ice_gathering_state()
*/
* otherwise a negative error value
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @post webrtc_ice_connection_state_change_cb() will be invoked.
* @see webrtc_unset_ice_connection_state_change_cb()
* @see webrtc_ice_connection_state_change_cb()
* @retval #WEBRTC_ERROR_NONE Successful
* @retval #WEBRTC_ERROR_INVALID_PARAMETER Invalid parameter
* @retval #WEBRTC_ERROR_INVALID_OPERATION Invalid operation
+ * @pre @a webrtc state must be set to #WEBRTC_STATE_IDLE.
* @see webrtc_set_ice_connection_state_change_cb()
* @see webrtc_get_ice_connection_state()
*/