public void namespace() {
DmdlSemantics world = resolve();
ModelDeclaration model = world.findModelDeclaration("simple");
assertThat(model.getSymbol(), is(model("simple")));
NamespaceTrait trait = model.getTrait(NamespaceTrait.class);
assertThat(trait, not(nullValue()));
assertThat(trait.getNamespace().toString(), is("com.example"));
}