@Test
    public void attributeExistence_MatchesShapesWithTrait() {
        // Simple existence check.
        assertThat(SelectorTest.exampleIds(attributeExistenceModel, "[trait|deprecated]"),
                containsInAnyOrder("smithy.example#DeprecatedString"));

        // Empty tags traits still exist.
        assertThat(SelectorTest.exampleIds(attributeExistenceModel, "[trait|tags]"),
                containsInAnyOrder("smithy.example#MyString2"));

        assertThat(SelectorTest.exampleIds(attributeExistenceModel, "[trait|enum]"),
                containsInAnyOrder("smithy.example#MyString3",
                        "smithy.example#MyString4",
                        "smithy.example#MyString5"));
    }
This is a kind of integration test of the examples in the
specification.

Each test "category" is prefixed with "[name]_" to group them.

TODO: It would be great to consolidate other tests from SelectorTest here to better organize tests.
smithy-model/src/test/java/software/amazon/smithy/model/selector/SpecIntegTest.java