code: def get_data_home(data_home=None):
      """Return the path of the tick data dir.
      This folder is used by some large dataset loaders to avoid
      downloading the data several times.
      By default the data dir is set to a folder named 'tick_datasets'
      in the user home folder.
      Alternatively, it can be set by the 'TICK_DATASETS' environment
      variable or programmatically by giving an explicit folder path. The
      '~' symbol is expanded to the user home folder.
      If the folder does not already exist, it is automatically created.
      """
      if data_home is None:
          if _TICK_HOME_ENV in os.environ:
              data_home = os.environ[_TICK_HOME_ENV]
          else:
              data_home = _TICK_DEFAULT_HOME
              warnings.warn(
                  "{} environment variable was not set. Saving dataset"
                  " to the default location {}".format(
                      _TICK_HOME_ENV, _TICK_DEFAULT_HOME
                  )
              )
  
      data_home = os.path.expanduser(data_home)
      if not os.path.exists(data_home):
          os.makedirs(data_home)
      return data_home
  
file_path: tick/tick/dataset/download_helper.py
imports: import logging
  from urllib.request import urlopen
  import os
  import shutil
  import numpy
  from sklearn.datasets import load_svmlight_file
  import math
  import warnings
label_desc: Use image node_id 5 for calling a global function with example usage: get_data_home(data_home) and returns: data_home