private static final List<List<Location>> gridWith(
List<Location> topRow, Location topLeft, Location bottomLeft) {
int rowCount = topLeft.equals(bottomLeft) ? 1 : topLeft.distanceFrom(bottomLeft) + 1;
return Stream.iterate(topRow, row -> row.stream().map(Location::south).collect(toList()))
.limit(rowCount)
.collect(toList());
}
private static final List<Location> topRowWith(Location topLeft, Location topRight) {
int columnCount = topLeft.equals(topRight) ? 1 : topLeft.distanceFrom(topRight) + 1;
return Stream.iterate(topLeft, Location::east).limit(columnCount).collect(toList());
}