class_docstr: Module level tests for all sktime forecasters.
class_docstr_tok: ["Module","level","tests","for","all","sktime","forecasters","."]
docstr: Check correct time index of update-predict.
docstr_tok: ["Check","correct","time","index","of","update-predict","."]
code: def test_update_predict_single(
      self, estimator_instance, n_columns, fh_int_oos, update_params
  ):
      """Check correct time index of update-predict."""
      y = _make_series(n_columns=n_columns)
      y_train, y_test = temporal_train_test_split(y)
      estimator_instance.fit(y_train, fh=fh_int_oos)
      y_pred = estimator_instance.update_predict_single(
          y_test, update_params=update_params
      )
      cutoff = get_cutoff(y_test, return_index=True)
      _assert_correct_pred_time_index(y_pred.index, cutoff, fh_int_oos)
      _assert_correct_columns(y_pred, y_train)
  
imports: import numpy
  import pandas
  import pytest
  from sktime.datatypes import check_is_mtype
  from sktime.datatypes._utilities import get_cutoff
  from sktime.exceptions import NotFittedError
  from sktime.forecasting.base._delegate import _DelegatedForecaster
  from sktime.forecasting.base._fh import ForecastingHorizon
  from sktime.forecasting.tests._config import TEST_ALPHAS, TEST_FHS, TEST_OOS_FHS, TEST_STEP_LENGTHS_INT, TEST_WINDOW_LENGTHS_INT, VALID_INDEX_FH_COMBINATIONS
  from sktime.performance_metrics.forecasting import mean_absolute_percentage_error
  from sktime.split import ExpandingWindowSplitter, SlidingWindowSplitter, temporal_train_test_split
  from sktime.tests.test_all_estimators import BaseFixtureGenerator, QuickTester
  from sktime.utils._testing.forecasting import _assert_correct_columns, _assert_correct_pred_time_index, _get_expected_index_for_update_predict, _get_n_columns, _make_fh, make_forecasting_problem
  from sktime.utils._testing.series import _make_series
  from sktime.utils.validation.forecasting import check_fh
label_desc: Use image node_id 18 for calling the TestAllForecasters obj's underlying member method code with example usage: obj.test_update_predict_single(estimator_instance, n_columns, fh_int_oos, update_params) without return types