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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 get_unconfirmed_tx(api_code=None):
 """Get a list of currently unconfirmed transactions. :param str api_code: Blockchain.info API code (optional) :return: an array of :class:`Transaction` objects """


    resource = 'unconfirmed-transactions?format=json'
    if api_code is not None:
        resource += '&api_code=' + api_code
    response = util.call_api(resource)
    json_response = json.loads(response)
    return [Transaction(t) for t in json_response['txs']]