def fetch_from_ttl(ttl_file)
      graph = RDF::Turtle::Reader.open(ttl_file, prefixes:  ROF::OsfPrefixList.dup)
      JSON::LD::API.fromRdf(graph)
    end
def fetch_from_ttl(ttl_file)
      graph = RDF::Turtle::Reader.open(ttl_file, prefixes:  ROF::OsfPrefixList.dup)
      JSON::LD::API.fromRdf(graph)
    end
reads a ttl file and makes it a JSON-LD file that we can parse