@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix ex: <http://example.org/shacl-test/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ex:s1 a sh:PropertyShape ;
  sh:targetNode ex:i ;
  sh:path ex:message ;
  sh:uniqueLang "1"^^xsd:boolean .

# Note that the value above is "1"^^xsd:boolean, which is distinct from "true"^^xsd:boolean.
# Only true is mentioned in the spec, meaning that "1" will not activate the constraint
# and the constraint is being ignored.