code: def ensure_pytz_is_installed():
      if not pytz_available:
          raise ImportError(
              "pytz must be installed in order to locate timezones. "
              "If geopy has been installed with `pip`, then pytz can be "
              'installed with `pip install "geopy[timezone]"`.'
          )
  
file_path: geopy/geopy/timezone.py
imports: from geopy.exc import GeocoderParseError
label_desc: Use image node_id 1 for calling a global function with example usage: ensure_pytz_is_installed() without return types