code: public void setContentLanguage(Locale locale) {
  		checkCommitted();
  		ContentLanguageHeader contentLanguageHeader =
  			SipFactoryImpl.headerFactory.createContentLanguageHeader(locale);
  		this.message.setContentLanguage(contentLanguageHeader);
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.SipServletMessage#setContentLanguage(java.util.Locale)