code: def to_df(self):
      holidays_df = pd.DataFrame(
          sorted(self.federal_holidays.items()),
          columns=["holiday_date", "names"],
      )
      holidays_df.holiday_date = holidays_df.holiday_date.astype(
          "datetime64[ns]"
      )
      return holidays_df
  
imports: from typing import Optional, Tuple
  import holidays
  import pandas
label_desc: Use image node_id 2 for calling the HolidayUtil obj's underlying member method code with example usage: obj.to_df() and returns: holidays_df