SOURCE

loadTerms: function(callback) {
  var self = this,
  arr = [],
  flag = true,
  listOfTerms = this.collectTermIDs();

  _(listOfTerms).each(function(term) {
    TaxonomyUi.TermRetriever.getTerms(term.id)
      .fail(function() {
      $.error("Could not get taxonomy data from the server");
    })
      .done(function(term) {
      arr.push(term);
      if (callback) {
        callback();
      }
    });
  });

  arr.forEach(function(term) {
    term.broader_terms.forEach(function(broaderTerm) {
      if (broaderTerm.id != term.id) {
        flag = false;
        break;
      }
    }) if (flag) {
      self.assignedTerms.add(term);
    }
  });
}