docs: function(container, progress, color) {
  		if (typeof container === 'number') {
  			color = progress;
  			progress = container;
  			container = 'body';
  		}
  		container = $(container || 'body');
  		if (container.length === 0) return;
  		container = container[0];
  		var progressbar;
  		if (container.classList.contains(CLASS_PROGRESSBAR)) {
  			progressbar = container;
  		} else {
  			var progressbars = container.querySelectorAll(SELECTOR_PROGRESSBAR + ':not(.' + CLASS_PROGRESSBAR_OUT + ')');
  			if (progressbars) {
  				for (var i = 0, len = progressbars.length; i < len; i++) {
  					var _progressbar = progressbars[i];
  					if (_progressbar.parentNode === container) {
  						progressbar = _progressbar;
  						break;
  					}
  				}
  			}
  			if (!progressbar) {
  				progressbar = document.createElement('span');
  				progressbar.className = CLASS_PROGRESSBAR + ' ' + CLASS_PROGRESSBAR_IN + (typeof progress !== 'undefined' ? '' : (' ' + CLASS_PROGRESSBAR_INFINITE)) + (color ? (' ' + CLASS_PROGRESSBAR + '-' + color) : '');
  				if (typeof progress !== 'undefined') {
  					progressbar.innerHTML = '<span></span>';
  				}
  				container.appendChild(progressbar);
  			} else {
  				progressbar.classList.add(CLASS_PROGRESSBAR_IN);
  			}
  		}
  		if (progress) setProgressbar(container, progress);
  		return progressbar;
  	}