void addRequestHeaderDontRepleace(String key,String value){
  if (userHeaders == null) {
    userHeaders=new Hashtable();
  }
  if (!userHeaders.containsKey(key)) {
    userHeaders.put(key,value);
  }
}

void addRequestHeaderDontRepleace ( String key , String value ) { if ( userHeaders == null ) { userHeaders = new Hashtable ( ) ; } if ( ! userHeaders . containsKey ( key ) ) { userHeaders . put ( key , value ) ; } }
adds the given header to the request that will be sent unless the header is already set to something else
