code: def parse_attributes(attributes=None, classname=None):
    
    if not attributes:
      attributes = {}
    attributes.setdefault('class', DEFAULT_CLASS_NAME)
    # If `classname` is specified, it overwrites `class` property in `attributes`.
    if classname:
      attributes['class'] = classname
    return attributes
docs: Parses attributes,
  
    Args:
      attributes (dict): Input attributes.
      classname (:obj:`str`, optional): Class name of output SPAN tags.
  
    Returns:
      Parsed attributes. (dict)