app/src/main/java/org/appspot/apprtc/WebSocketChannelClient.java
// called on a looper thread.
called on a looper thread.
called on a looper thread .
private void checkIfCalledOnValidThread() {
        if (!executor.checkOnLooperThread()) {
            throw new IllegalStateException(
                    "WebSocket method is not called on valid thread");
        }
    }
private void checkIfCalledOnValidThread ( ) { if ( ! executor . checkOnLooperThread ( ) ) { throw new IllegalStateException ( "WebSocket method is not called on valid thread" ) ; } }
called on a looper thread.
called on a looper thread .