@Test
  public void shouldValidateNonJSONObject() {
    assertFalse(StringUtils.isJsonObject("foobar"));
    assertFalse(StringUtils.isJsonObject("0.5"));
    assertFalse(StringUtils.isJsonObject("1,244.0"));
  }
A dummy key which is longer than allowed.
src/test/java/net/spy/memcached/util/StringUtilsTest.java