code: def _normalize_name(name):
    
    if isinstance(name, tuple):
      ns, nm = name
      return "{}:{}".format(ns, nm)
    else:
      return name
docs: Returns a normalized element tag or attribute name. A tag name or attribute name can be given
    either as a string, or as a 2-tuple. If a 2-tuple, it is interpreted as (namespace, name) and is
    returned joined by a colon ":"
  
    :name: a string or a 2-tuple of strings