@classmethod
def _from_dict(cls, _dict):
    """Initialize a Firewall object from a json dictionary."""
    args = {}
    validKeys = ['allowed_ip']
    badKeys = set(_dict.keys()) - set(validKeys)
    if badKeys:
        raise ValueError(
            'Unrecognized keys detected in dictionary for class Firewall: ' +
            ', '.join(badKeys))
    if 'allowed_ip' in _dict:
        args['allowed_ip'] = _dict.get('allowed_ip')
    return cls(**args)
