code: public void addHeader(String name, String value) {
  		if(logger.isDebugEnabled()) {
  			logger.debug("addHeader - name=" + name + ", value=" + value);
  		}
  
  		checkCommitted();
  		addHeaderInternal(name, value, false);
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.SipServletMessage#addHeader(java.lang.String, java.lang.String)