Add unit tests for xOffset and yOffset setting. Progress on #99.
Add unit tests for xOffset and yOffset setting. Progress on #99.

gdseller/plottable,RobertoMalatesta/plottable,palantir/plottable,iobeam/plottable,alyssaq/plottable,alyssaq/plottable,iobeam/plottable,onaio/plottable,danmane/plottable,NextTuesday/plottable,palantir/plottable,jacqt/plottable,softwords/plottable,danmane/plottable,jacqt/plottable,softwords/plottable,RobertoMalatesta/plottable,jacqt/plottable,danmane/plottable,onaio/plottable,NextTuesday/plottable,NextTuesday/plottable,onaio/plottable,softwords/plottable,alyssaq/plottable,palantir/plottable,gdseller/plottable,palantir/plottable,iobeam/plottable,RobertoMalatesta/plottable,gdseller/plottable