@Override public synchronized void addRequestProperty(String key,String value){
  if (connected || connecting)   throw new IllegalStateException("Already connected");
  if (key == null)   throw new NullPointerException("key is null");
  if (isExternalMessageHeaderAllowed(key,value)) {
    requests.add(key,value);
    if (!key.equalsIgnoreCase("Content-Type")) {
      userHeaders.add(key,value);
    }
  }
}

@ Override public synchronized void addRequestProperty ( String key , String value ) { if ( connected || connecting ) throw new IllegalStateException ( "Already connected" ) ; if ( key == null ) throw new NullPointerException ( "key is null" ) ; if ( isExternalMessageHeaderAllowed ( key , value ) ) { requests . add ( key , value ) ; if ( ! key . equalsIgnoreCase ( "Content-Type" ) ) { userHeaders . add ( key , value ) ; } } }
adds a general request property specified by a key - value pair . this method will not overwrite existing values associated with the same key .
