code: function stringifyStyle(style) {
    if (typeof style === 'string') {
      return style;
    }
    var values = [];
    for (var key in style) {
      values.push(key + ':' + style[key]);
    }
    return values.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.