def AddComment(self, comment=''):
    if self.text:
      if comment and comment not in self.text:
        self.text += ', ' + comment
    else:
      self.text = comment
Convert the libcloud Node object into something more serializable.
dataset/ETHPy150Open google/capirca/lib/nacaddr.py/IPv4.AddComment--crossover with--dataset/ETHPy150Open saltstack/salt/salt/cloud/clouds/gce.py/_expand_node