public void setPresence(boolean present) {
        if (this.present == present)
            return;
        this.present = present;
        updateVague();
        if (present) {
            firePresence(true);
        } else {
            fireLeaving();
        }
    }
public void setPresence(boolean present) {
        if (this.present == present)
            return;
        this.present = present;
        updateVague();
        if (present) {
            firePresence(true);
        } else {
            fireLeaving();
        }
    }
public void setPresence ( boolean present ) { if ( this . present == present ) return ; this . present = present ; updateVague ( ) ; if ( present ) { firePresence ( true ) ; } else { fireLeaving ( ) ; } }
sets the presence
@param present true for presence, false if not
sets the presence