code: def load_split_data():
      y, X = load_longley()
      y_train, y_test, X_train, X_test = temporal_train_test_split(y, X)
      return X_train
  
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  from sktime.datasets import load_airline, load_longley, load_PBS_dataset
  from sktime.split import temporal_train_test_split
  from sktime.tests.test_switch import run_test_for_class
  from sktime.transformations.series.date import DateTimeFeatures
  from sktime.utils._testing.hierarchical import _make_hierarchical
label_desc: Use image node_id 1 for calling a global function with example usage: load_split_data() and returns: X_train