docs: public static boolean[][] cloneAdjacencyMarix(boolean[][] src) {
          int length = src.length;
          boolean[][] target = new boolean[length][src[0].length];
          for (int i = 0; i < length; i++) {
              System.arraycopy(src[i], 0, target[i], 0, src[i].length);
          }
          return target;
      }