code: def get_holidays_from_country(
      country: Union[str, Iterable[str]], df=None
  ):
      """
      Return all possible holiday names of given country
  
      Parameters
      ----------
          country : str, list
              List of country names to retrieve country specific holidays
          df : pd.Dataframe
              Dataframe from which datestamps will be retrieved from
  
      Returns
      -------
          set
              All possible holiday names of given country
      """
      if df is None:
          years = np.arange(1995, 2045)
      else:
          dates = df["ds"].copy(deep=True)
          years = list({x.year for x in dates})
      # support multiple countries
      if isinstance(country, str):
          country = [country]
  
      unique_holidays = {}
      for single_country in country:
          holidays_country = get_country_holidays(single_country, years)
          for date, name in holidays_country.items():
              if date not in unique_holidays:
                  unique_holidays[date] = name
      holiday_names = unique_holidays.values()
      return set(holiday_names)
  
imports: from __future__ import annotations
  import logging
  import math
  import os
  import sys
  from collections import OrderedDict
  from typing import TYPE_CHECKING, Iterable, Optional, Union
  import numpy
  import pandas
  import pytorch_lightning
  import torch
  from neuralprophet import utils_torch
  from neuralprophet.hdays_utils import get_country_holidays
  from neuralprophet.logger import ProgressBar
label_desc: Use image node_id 13 for calling a global function with example usage: get_holidays_from_country(country, df) and returns: set