src/net/java/sip/communicator/service/protocol/CallConference.java
/**
     * Adds a specific <tt>Call</tt> to the list of <tt>Call</tt>s participating
     * in this telephony conference.
     *
     * @param call the <tt>Call</tt> to add to the list of <tt>Call</tt>s
     * participating in this telephony conference
     * @return <tt>true</tt> if the list of <tt>Call</tt>s participating in this
     * telephony conference changed as a result of the method call; otherwise,
     * <tt>false</tt>
     * @throws NullPointerException if <tt>call</tt> is <tt>null</tt>
     */
Adds a specific Call to the list of Calls participating
in this telephony conference.

@param call the Call to add to the list of Calls
participating in this telephony conference
@return true if the list of Calls participating in this
telephony conference changed as a result of the method call; otherwise,
false
@throws NullPointerException if call is null
Adds a specific Call to the list of Calls participating in this telephony conference . @param call the Call to add to the list of Calls participating in this telephony conference @return true if the list of Calls participating in this telephony conference changed as a result of the method call ; otherwise false @throws NullPointerException if call is null
boolean addCall(Call call)
    {
        if (call == null)
            throw new NullPointerException("call");
        synchronized (callsSyncRoot)
        {
            if (mutableCalls.contains(call))
                return false;
            /*
             * Implement the List of Calls participating in this telephony
             * conference as a copy-on-write storage in order to optimize the
             * getCalls method which is likely to be executed much more often
             * than the addCall and removeCall methods.
             */
            List<Call> newMutableCalls = new ArrayList<Call>(mutableCalls);
            if (newMutableCalls.add(call))
            {
                mutableCalls = newMutableCalls;
                immutableCalls = Collections.unmodifiableList(mutableCalls);
            }
            else
                return false;
        }
        callAdded(call);
        return true;
    }
boolean addCall ( Call call ) { if ( call == null ) throw new NullPointerException ( "call" ) ; synchronized ( callsSyncRoot ) { if ( mutableCalls . contains ( call ) ) return false ; /*
             * Implement the List of Calls participating in this telephony
             * conference as a copy-on-write storage in order to optimize the
             * getCalls method which is likely to be executed much more often
             * than the addCall and removeCall methods.
             */ List < Call > newMutableCalls = new ArrayList < Call > ( mutableCalls ) ; if ( newMutableCalls . add ( call ) ) { mutableCalls = newMutableCalls ; immutableCalls = Collections . unmodifiableList ( mutableCalls ) ; } else return false ; } callAdded ( call ) ; return true ; }
Adds a specific <tt>Call</tt> to the list of <tt>Call</tt>s participating
 in this telephony conference.
Adds a specific <tt > Call< / tt > to the list of <tt > Call< / tt > s participating in this telephony conference .