I just ran grep -R '@prefix ex:' and noticed that the test IRIs are either similar to this...

./tests/sparql/pre-binding/unsupported-sparql-001.ttl:@prefix ex: <http://datashapes.org/sh/tests/sparql/pre-binding/unsupported-sparql-001.test#> .

... or this:

./tests/core/node/xone-duplicate-data.ttl:@prefix ex: <http://example.org/shacl-test/> .

Should these be unified, in domain and path style? The former scopes tests' IRIs nicely, but the latter avoids introducing a domain outside of W3C.