ImageGetPixelTest

 void ImageGetPixelTest(){
      auto side = Tile::SIZE;
      Size size{side * 2 + 3, side * 2 + 5};
      const char color = 'g';
      const Image img(size, color);
      for (auto x = 0; x < size.width; ++x){
        for (auto y = 0; y < size.height; ++y){
          ASSERT_EQUAL(img.GetPixel({x, y}), color);
        }
      }

      char blank = ' ';
      ASSERT_EQUAL(img.GetPixel({-1, 2}), blank);
      ASSERT_EQUAL(img.GetPixel({1, -2}), blank);
      ASSERT_EQUAL(img.GetPixel({side*5, 2}), blank);
      ASSERT_EQUAL(img.GetPixel({2, side*5}), blank);
    }