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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 ext_pillar(minion_id,  # pylint: disable=W0613
               pillar,  # pylint: disable=W0613
               command):
    '''
    Execute a command and read the output as JSON
    '''
    try:
        command = command.replace('%s', minion_id)
        return salt.utils.json.loads(__salt__['cmd.run'](command))
    except Exception:
        log.critical('JSON data from %s failed to parse', command)
        return {}