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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 is_exported(bundle):
 """ Returns True if dataset is already exported to CKAN. Otherwise returns False. """

    if not ckan:
        raise EnvironmentError(MISSING_CREDENTIALS_MSG)
    params = {'q': 'name:{}'.format(bundle.dataset.vid.lower())}
    resp = ckan.action.package_search(**params)
    return len(resp['results']) > 0