code: public static void matrixCopy(Object[][] src, Object[][] dest) {
          if (src != null && dest != null) {
              for (int i = 0; i < src.length; i++) {
                  System.arraycopy(src[i], 0, dest[i], 0, src[i].length);
              }
          }
      }
docs: Copies a 2D array. Nothing happens if either argument is
  <code>null</code>.
  
  @param src an array.
  @param dest an array.