src/net/java/sip/communicator/service/protocol/CallConference.java
/**
     * Adds a <tt>CallPeerConferenceListener</tt> to the <tt>CallPeer</tt>s
     * associated with the <tt>Call</tt>s participating in this telephony
     * conference. The method is a convenience that takes on the responsibility
     * of tracking the <tt>Call</tt>s that get added/removed to/from this
     * telephony conference and the <tt>CallPeer</tt> that get added/removed
     * to/from these <tt>Call</tt>s.
     *
     * @param listener the <tt>CallPeerConferenceListener</tt> to be added to
     * the <tt>CallPeer</tt>s associated with the <tt>Call</tt>s participating
     * in this telephony conference
     * @throws NullPointerException if <tt>listener</tt> is <tt>null</tt>
     */
Adds a CallPeerConferenceListener to the CallPeers
associated with the Calls participating in this telephony
conference. The method is a convenience that takes on the responsibility
of tracking the Calls that get added/removed to/from this
telephony conference and the CallPeer that get added/removed
to/from these Calls.

@param listener the CallPeerConferenceListener to be added to
the CallPeers associated with the Calls participating
in this telephony conference
@throws NullPointerException if listener is null
Adds a CallPeerConferenceListener to the CallPeers associated with the Calls participating in this telephony conference . The method is a convenience that takes on the responsibility of tracking the Calls that get added / removed to / from this telephony conference and the CallPeer that get added / removed to / from these Calls . @param listener the CallPeerConferenceListener to be added to the CallPeers associated with the Calls participating in this telephony conference @throws NullPointerException if listener is null
public void addCallPeerConferenceListener(
            CallPeerConferenceListener listener)
    {
        if (listener == null)
            throw new NullPointerException("listener");
        else
        {
            synchronized (callPeerConferenceListeners)
            {
                if (!callPeerConferenceListeners.contains(listener))
                    callPeerConferenceListeners.add(listener);
            }
        }
    }
public void addCallPeerConferenceListener ( CallPeerConferenceListener listener ) { if ( listener == null ) throw new NullPointerException ( "listener" ) ; else { synchronized ( callPeerConferenceListeners ) { if ( ! callPeerConferenceListeners . contains ( listener ) ) callPeerConferenceListeners . add ( listener ) ; } } }
Adds a <tt>CallPeerConferenceListener</tt> to the <tt>CallPeer</tt>s
 associated with the <tt>Call</tt>s participating in this telephony
 conference.
Adds a <tt > CallPeerConferenceListener< / tt > to the <tt > CallPeer< / tt > s associated with the <tt > Call< / tt > s participating in this telephony conference .