Return a description of this user.

def Describe(self):
    """Return a description of this user."""
    result = ["\nUsername: %s" % self.urn.Basename()]
    labels = [l.name for l in self.GetLabels()]
    result.append("Labels: %s" % ",".join(labels))

    if self.Get(self.Schema.PASSWORD) is None:
      result.append("Password: not set")
    else:
      result.append("Password: set")

    return "\n".join(result)