code: def load_PBS_dataset():
      """Load the Pharmaceutical Benefit Scheme univariate time series dataset [1]_.
  
      Returns
      -------
      y : pd.Series
       Time series
  
      Examples
      --------
      >>> from sktime.datasets import load_PBS_dataset
      >>> y = load_PBS_dataset()
  
      Notes
      -----
      The Pharmaceutical Benefits Scheme (PBS) is the Australian government drugs
      subsidy scheme.
      Data comprises of the numbers of scripts sold each month for immune sera
      and immunoglobulin products in Australia.
  
  
      Dimensionality:     univariate
      Series length:      204
      Frequency:          Monthly
      Number of cases:    1
  
      The time series is intermittent, i.e contains small counts,
      with many months registering no sales at all,
      and only small numbers of items sold in other months.
  
      References
      ----------
      .. [1] Data for "Forecasting: Principles and Practice" (3rd Edition)
      """
      name = "PBS_dataset"
      fname = name + ".csv"
      path = os.path.join(MODULE, DIRNAME, name, fname)
      y = pd.read_csv(path, index_col=0, dtype={1: float}).squeeze(
          "columns"
      )
  
      # make sure time index is properly formatted
      y.index = pd.PeriodIndex(y.index, freq="M", name="Period")
      y.name = "Number of scripts"
      return y
  
imports: import os
  import zipfile
  from urllib.error import HTTPError, URLError
  from warnings import warn
  import numpy
  import pandas
  from sktime.datasets._data_io import _download_and_extract, _list_available_datasets, _load_dataset, _load_provided_dataset
  from sktime.datasets._readers_writers.tsf import load_tsf_to_dataframe
  from sktime.datasets.tsf_dataset_names import tsf_all, tsf_all_datasets
  from sktime.utils.validation._dependencies import _check_soft_dependencies
label_desc: Use image node_id 19 for calling a global function with example usage: load_PBS_dataset() and returns: y