code: public void setExpires(int seconds) throws IllegalArgumentException {
  		javax.sip.address.URI uri = this.getAddress().getURI();
  
  		if (uri instanceof SipURI) {
  			/*
  			SipURI sipUri = (SipURI) uri;
  			try {
  				sipUri.setParameter(EXPIRES_PARAM_NAME, Integer.toString(seconds));
  			} catch (ParseException e) {
  				throw new IllegalArgumentException("Problem setting parameter",
  						e);
  			}*/
  			if(seconds == -1) {
  				this.removeParameter(EXPIRES_PARAM_NAME);
  				return;
  			}
  			this.setParameter(EXPIRES_PARAM_NAME, Integer.toString(seconds));
  		} else {
  			throw new IllegalArgumentException(
  					"Can only set parameter for Sip URI");
  		}
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.Address#setExpires(int)