code: function (kb, x, displayables) {
        var t = kb.findTypeURIs(subject)
        for (var k = 0; k < displayables.length; k++) {
          if ($rdf.Util.mediaTypeClass(displayables[k]).uri in t) {
            return true
          }
        }
        return false
      }
docs: This data coul d come from a fetch OR from ldp comtaimner