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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def api(server, command, *args, **kwargs):
    '''
    Call the Spacewalk xmlrpc api.

    CLI Example:

    .. code-block:: bash

        salt-run spacewalk.api spacewalk01.domain.com systemgroup.create MyGroup Description
        salt-run spacewalk.api spacewalk01.domain.com systemgroup.create arguments='["MyGroup", "Description"]'

    State Example:

    .. code-block:: yaml

        create_group:
          salt.runner:
            - name: spacewalk.api
            - server: spacewalk01.domain.com
            - command: systemgroup.create
            - arguments:
              - MyGroup
              - Description
    '''
    if 'arguments' in kwargs:
        arguments = kwargs['arguments']
    else:
        arguments = args

    call = '{0} {1}'.format(command, arguments)
    try:
        client, key = _get_session(server)
    except Exception as exc:
        err_msg = 'Exception raised when connecting to spacewalk server ({0}): {1}'.format(server, exc)
        log.error(err_msg)
        return {call: err_msg}

    namespace, method = command.split('.')
    endpoint = getattr(getattr(client, namespace), method)

    try:
        output = endpoint(key, *arguments)
    except Exception as e:
        output = 'API call failed: {0}'.format(e)

    return {call: output}