code: function stringifyAttrs(attrs, tagName) {
    if (!attrs) {
      return '';
    }
    var attributes = [], value;
    for (var key in attrs) {
      value = attrs[key];
      if (key === 'style') {
        value = stringifyStyle(value);
      } else if (key === 'class') {
        value = stringifyClass(value);
      }
      attributes.push(key + '="' + String(value).replace(/"/g, '\\"') + '"');
    }
    return attributes.join(' ');
  }
docs: Returns a `'key1='value1' key2='value2' ...'` string from
  a `{ key1: 'value1', key2: 'value2' }` object.
  
  @param  Object attrs The keys/values object to stringify.
  @return String       The corresponding string.