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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 list_worker_processes(apppool):
    '''
    Returns a list of worker processes that correspond to the passed
    application pool.

    .. versionadded:: 2017.7.0

    Args:
        apppool (str): The application pool to query

    Returns:
        dict: A dictionary of worker processes with their process IDs

    CLI Example:

    .. code-block:: bash

        salt '*' win_iis.list_worker_processes 'My App Pool'
    '''
    ps_cmd = ['Get-ChildItem',
              r"'IIS:\AppPools\{0}\WorkerProcesses'".format(apppool)]

    cmd_ret = _srvmgr(cmd=ps_cmd, return_json=True)

    try:
        items = salt.utils.json.loads(cmd_ret['stdout'], strict=False)
    except ValueError:
        raise CommandExecutionError('Unable to parse return data as Json.')

    ret = dict()
    for item in items:
        ret[item['processId']] = item['appPoolName']

    if not ret:
        log.warning('No backups found in output: %s', cmd_ret)

    return ret