 pre.setAttribute('data-line', line)
                    code.textContent = 'Loading…';
                    pre.appendChild(code);

                    var xhr = new XMLHttpRequest();

                    xhr.open('GET', src, true);

                    xhr.onreadystatechange = function () {
                        if (xhr.readyState !== 4) {
                            return;
                        }

                        if (xhr.status < 400 && xhr.responseText) {
                            code.t