code: public void answer(final Context context, Listener newListener) {
          if (!caller) {
              listenerReference = new WeakReference<Listener>(newListener);
  
              getTurnServerCredentials(new Respoke.TaskCompletionListener() {
                  @Override
                  public void onSuccess() {
                      initializePeerConnection(context);
                      addLocalStreams(context);
                      processRemoteSDP();
                  }
  
                  @Override
                  public void onError(String errorMessage) {
                      postErrorToListener(errorMessage);
                  }
              });
          }
      }
docs: Answer the call and start the process of obtaining media. This method is called automatically on the caller's
  side. This method must be called on the callee's side to indicate that the endpoint does wish to accept the
  call.
  
  @param context      An application context with which to access shared resources
  @param newListener  A listener to receive notifications of call-related events