docs: function FormatStackTrace(error, frames) {
        var lines = [];
        try {
          lines.push(error.toString());
        } catch (e) {
          try {
            lines.push("<error: " + e + ">");
          } catch (ee) {
            lines.push("<error>");
          }
        }
        for (var i = 0; i < frames.length; i++) {
          var frame = frames[i];
          var line;
          try {
            line = FormatSourcePosition(frame);
          } catch (e) {
            try {
              line = "<error: " + e + ">";
            } catch (ee) {
              // Any code that reaches this point is seriously nasty!
              line = "<error>";
            }
          }
          lines.push("    at " + line);
        }
        return lines.join("\n");
      }