@Test
 public void getValidKey() throws Exception {
   Assert.assertNull(dataTable.get("one"));
   Storeable value = new StoreableDataValue(types);
   value.setColumnAt(0, 5);
   value.setColumnAt(1, "book");
   dataTable.put("favourite", value);
   Assert.assertEquals(dataTable.get("favourite"), value);
 }
 @Test(expected = IllegalArgumentException.class)
 public void getNullKeyShouldFail() throws Exception {
   dataTable.get(null);
 }
 @Test(expected = IllegalStateException.class)
 public void closeTableGetShouldFail() throws Exception {
   dataTable.close();
   dataTable.get("key");
 }