I have a MBA with a Thunderbolt port. Yesterday I bought a Roku Stick which works great on a TV with a HDMI input. I was hoping to use the Roku for travel, interfacing it with a Thunderbolt-HDMI adapter that I've have for a couple of years. I want to see the Roku Stick output on my MBA if possilble, but when I hook it up with my adapter, it doesn't work. Is the Thunderbolt port ONLY one way out of my MBA? The Roku Stick only outputs via HDMI.