Adding temporary file 'Spiral.java' which does not fall under any package.
This is my temporary scatch pad to figure out how to make the proper xOff/yOff
iteration in BlockPlacementStrategy, which starts from somewhere near the
middle and expands outwards. This is trickier than I originally thought, and
so I'm saving this work under source control, until it's perfect, at which
point it will be moved into BlockPlacementStrategy.
