Well, that's how I had implemented it originally (forgot to update the javadoc). 

The issue with adding it here is that this method could potentially be called multiple times on the
same request via "addRequestProperty". For eg.

conn.addRequestProperty("X-Android-Transports", "spdy/3");
conn.addRequestProperty("X-Android-Transports", "http/1.1");

It seems a bit messy to handle that down here.