private void setTesterOnTest() {
        try {
            Field field = getTestClass().getJavaClass().getField("tester");
            if (field != null && field.getType().equals(PolicyTester.class)) {
                field.set(null, this);
            }
        } catch (Exception e) {
            return;
        }
    }
Sets the engine instance on the test class, assuming the test class
has a static field named engine of type {@link IEngine}.
test/policies/src/main/java/io/apiman/test/policies/PolicyTester.java