docs: def is_uuid4(instr):
    """A validator to confirm a string is indeed a UUID4
  
    :param instr: input string that may be uuid4
    :type instr: String
    :return: true if it is in UUID4 format
    :rtype: bool
    """
    v = instr.strip().replace('-','').lower()
    if len(v) != 32: return False
    if not re.match('^[0-9a-f]+$',v): return False
    if v[12] != '4': return False
    if not re.match('[89ab]',v[16]): return False
    return True