rotate180 method
Implementation
UBitMatrix rotate180() {
final UBitMatrix out = UBitMatrix(width, height);
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
if (get(x, y)) out.set(width - 1 - x, height - 1 - y);
}
}
return out;
}