def setUp(self):
        itau_data = get_itau_data_from_file()
        self.header_arquivo = itau_data['header_arquivo']
        self.seg_p = itau_data['seg_p1']
        self.seg_p_str = itau_data['seg_p1_str']
        self.seg_q = itau_data['seg_q1']
        self.seg_q_str = itau_data['seg_q1_str']
def _getN(self, n):
        n -= 1
        p = self.head
        while n:
            p = p.next
            n -= 1
        return p