def test_leitura_campo_alfa(self):
        self.assertEqual(self.header_arquivo.cedente_nome,
                         'TRACY TECNOLOGIA LTDA ME')
def dfs_print(root):
        if root is None:
            return
        dfs_print(root.left)
        print(str(root.key) + ' ', end='')
        dfs_print(root.right)