code: @Test public void testDataMatrixImageWriter(){
    Map<EncodeHintType,Object> hints=new EnumMap<EncodeHintType,Object>(EncodeHintType.class);
    hints.put(EncodeHintType.DATA_MATRIX_SHAPE,SymbolShapeHint.FORCE_SQUARE);
    int bigEnough=64;
    DataMatrixWriter writer=new DataMatrixWriter();
    BitMatrix matrix=writer.encode("Hello Google",BarcodeFormat.DATA_MATRIX,bigEnough,bigEnough,hints);
    assertNotNull(matrix);
    assertTrue(bigEnough >= matrix.getWidth());
    assertTrue(bigEnough >= matrix.getHeight());
  }
  