code: protected String generateOffer() throws OpenViduException {
  		if (this.isWeb()) {
  			if (webEndpoint == null) {
  				throw new OpenViduException(Code.MEDIA_WEBRTC_ENDPOINT_ERROR_CODE,
  						"Can't generate offer when WebRtcEndpoint is null (ep: " + endpointName + ")");
  			}
  			return webEndpoint.generateOffer();
  		} else {
  			if (endpoint == null) {
  				throw new OpenViduException(Code.MEDIA_RTP_ENDPOINT_ERROR_CODE,
  						"Can't generate offer when RtpEndpoint is null (ep: " + endpointName + ")");
  			}
  			return endpoint.generateOffer();
  		}
  	}
docs: Orders the internal endpoint ({@link RtpEndpoint} or {@link WebRtcEndpoint})
  to generate the offer String that can be used to initiate a connection.
  
  @see SdpEndpoint#generateOffer()
  @return the Sdp offer