def check_host(netloc, username=None, password=None, namespace=None):
    """
    Checks if we can connect to a host with a known key.

    This will raise an exception if we cannot connect to the host. The
    exception will be one of BadHostKeyError, UnknownHostKeyError, or
    SCMError.
    """
    from django.conf import settings

    client = SSHClient(namespace=namespace)
    client.set_missing_host_key_policy(RaiseUnknownHostKeyPolicy())

    kwargs = {}

    if ':' in netloc:
        hostname, port = netloc.split(':')

        try:
            port = int(port)
        except ValueError:
            raise SSHInvalidPortError(port)
    else:
        hostname = netloc
        port = SSH_PORT

    # We normally want to notify on unknown host keys, but not when running
    # unit tests.
    if getattr(settings, 'RUNNING_TEST', False):
        client.set_missing_host_key_policy(paramiko.WarningPolicy())
        kwargs['allow_agent'] = False

    try:
        client.connect(hostname, port, username=username, password=password,
                       pkey=client.get_user_key(), **kwargs)
    except paramiko.BadHostKeyException as e:
        raise BadHostKeyError(e.hostname, e.key, e.expected_key)
    except paramiko.AuthenticationException as e:
        # Some AuthenticationException instances have allowed_types set,
        # and some don't.
        allowed_types = getattr(e, 'allowed_types', [])

        if allowed_types in 'publickey':
            key = client.get_user_key()
        else:
            key = None

        raise SSHAuthenticationError(allowed_types=allowed_types, user_key=key)
    except paramiko.SSHException as e:
        msg = six.text_type(e)
        if msg == 'No authentication methods available':
            raise SSHAuthenticationError
        else:
            raise SSHError(msg)
dataset/ETHPy150Open reviewboard/reviewboard/reviewboard/ssh/utils.py/check_host/swapped operands of `in`