def __init__(self, envvar, required=True, default=None, **kwargs):
    if ((not default) and envvar and (envvar in os.environ)):
        default = os.environ[envvar]
    if (required and default):
        required = False
    super(CBEnvAction, self).__init__(default=default, required=required, **kwargs)
def __init__(self, envvar, required=True, default=None, **kwargs):
    if ((not default) and envvar and (envvar in os.environ)):
        default = os.environ[envvar]
    if (required and default):
        required = False
    super(CBEnvAction, self).__init__(default=default, required=required, **kwargs)