public void testEvaluate() {
    Upper upper = Upper.getInstance();

    // Test empty string.
    TextValue textValue = (TextValue) upper.evaluate(Lists.<Value>newArrayList(new TextValue("")));
    assertEquals(textValue.getValue(), "");

    // Basic test.
    textValue = (TextValue) upper.evaluate(Lists.<Value>newArrayList(new TextValue("aBc")));
    assertEquals(textValue.getValue(), "ABC");
  }