private void setCellBlocked(
     final PartitionPatch patch, final int cellOffsetX, final int cellOffsetY) {
   final int dx = cellOffsetX + this.m_x;
   final int dy = cellOffsetY + this.m_y;
   for (int y = 0; y < 9; ++y) {
     for (int x = 0; x < 9; ++x) {
       if (patch == null || patch.isBlocked(x, y)) {
         this.setCellBlocked(x + dx, y + dy, true);
       }
     }
   }
 }