[confused] HexagonalTiledMapRenderer only displaying one hex.

I've been using this example: http://useof.org/java-open-source/com.badlogic.gdx.maps.tiled.renderers.HexagonalTiledMapRenderer - but when my app runs it only displays one hex tile in the bottom left of the screen.

Each run the hex is randomised, so I assume it's drawing either the first or last tile the code randomly selects.

I'm probably doing something stupid, any ideas?

HexagonalTiledMapRenderer is supposed to draw a CIV-style map of interlocking hexes, right?