blank nodes in ntriples format aren't parsed correctly

[zozlak]

$parser = new pietercolpaert\hardf\TriGParser(['format' => 'application/ntriples']);
$parser->parse('_:r1 <https://foo.bar> "baz".');

throws an Unexpected "blank" on line 1. error while

• Blank node is valid in the ntriples format (see the w3c specification).
• Same code with an URI works:

  $parser = new pietercolpaert\hardf\TriGParser(['format' => 'application/ntriples']);
  $parser->parse('<https://foo.bar> <https://foo.bar> "baz".');

This might be simply an issue with specifying the right format but I didn't find the list of formats to be used for particular RDF serializations.