code: public void setAcceptLanguage(Locale locale) {
  		checkCommitted();
  		AcceptLanguageHeader alh = SipFactoryImpl.headerFactory
  				.createAcceptLanguageHeader(locale);
  
  		this.message.setHeader(alh);
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.SipServletMessage#setAcceptLanguage(java.util.Locale)