text: Prism.hooks.add('after-highlight', function (env) {
  	// works only for <code> wrapped inside <pre data-line-numbers> (not inline)
  	var pre = env.element.parentNode;
  	if (!pre || !/pre/i.test(pre.nodeName) || pre.className.indexOf('line-numbers') === -1) {
  		return;
  	}
  
  	var linesNum = (1 + env.code.split('\n').length);
  	var lineNumbersWrapper;
  
  	lines = new Array(linesNum);
  	lines = lines.join('<span></span>');
  
  	lineNumbersWrapper = document.createElement('span');
  	lineNumbersWrapper.className = 'line-numbers-rows';
  	lineNumbersWrapper.innerHTML = lines;
  
  	if (pre.hasAttribute('data-start')) {
  		pre.style.counterReset = 'linenumber ' + (parseInt(pre.getAttribute('data-start'), 10) - 1);
  	}
  
  	env.element.appendChild(lineNumbersWrapper);
  
  });