KutaBeach questions

• Is this Singleton a thread-safe one?
• How does the GWT sinkEvent functionality works?
• GWT: how can I change browser tab name?
• Is this code a thread-safe one?
• HTTP: what are the relations between pipelining, keep-alive and Server Sent Events?
• Is there a way to replace class by another one in Intellij Idea?

KutaBeach answers