to this element's configuration, you must call this
     * function to kick off another analysis pass.
     */
    analyze: function() {
      if (!this.src) {
        return;
      }
      // We can implement request cancellation when someone needs it.
      if (this.loading) {
        console.error('Analyzer is already loading a document:', this);
        return;
      }
      this._setLoading(true);

      var options = {
        clean:  this.clean,
        filter: this.transitive ? function() { return f