public void testCovariance() {
    final ParserContext parserContext = new ParserContext();
    parserContext.setStrictTypeEnforcement(true);
    parserContext.setStrongTyping(true);
    parserContext.addInput("this", ImplementationA.class);
    assertEquals(int.class, MVEL.analyze("b.value", parserContext));
    assertEquals(42, MVEL.executeExpression(MVEL.compileExpression("b.value", parserContext), new ImplementationA()));
  }