Demonstrate the initialization and modification of a Tiled Map Service layer.
Example: http://tilecache.osgeo.org/wms-c/Basic.py/, basic, jpg
The first input must be an HTTP URL pointing to a TMS instance. The second
input must be a layer name available from that instance, and the third must
be the output format used by that layer. (Any other behavior will result in
broken images being displayed.)