code: def _generate_schedule(
      start_date: dateslib.DateTensor,
      end_date: dateslib.DateTensor,
      coupon_frequency: dateslib.PeriodTensor,
      calendar: dateslib.HolidayCalendar,
      roll_convention: dateslib.BusinessDayConvention,
      settlement_days: tf.Tensor,
      end_of_month: bool = False,
      first_coupon_date: Optional[dateslib.DateTensor] = None,
      penultimate_coupon_date: Optional[dateslib.DateTensor] = None,
  ) -> tf.Tensor:
      """Method to generate coupon dates.
  
      Args:
        start_date: Starting dates of schedule.
        end_date: End dates of the schedule.
        coupon_frequency: A `PeriodTensor` specifying the frequency of coupon
          payments.
        calendar: calendar: An instance of `BankHolidays`.
        roll_convention: Business day roll convention of the schedule.
        settlement_days: An integer `Tensor` with the shape compatible with
          `start_date` and `end_date` specifying the number of settlement days.
        end_of_month: Python `bool`. If `True`, shifts all dates in schedule to
          the ends of corresponding months, if `start_date` or `end_date` (
          depending on `backward`) is at the end of a month. The shift is applied
          before applying `roll_convention`.
        first_coupon_date: First day of the irregular coupon, if any.
        penultimate_coupon_date: Penultimate day of the coupon, if any.
  
      Returns:
        A `DateTensor` containing the generated date schedule of shape
        `batch_shape + [max_num_coupon_days]`, where `max_num_coupon_days` is the
        number of coupon days for the longest living swap in the batch. The coupon
        days for the rest of the swaps are padded with their final coupon day.
      """
      if (
          first_coupon_date is not None
          and penultimate_coupon_date is not None
      ):
          raise ValueError(
              "Only first or last coupon dates can be specified "
              " for an irregular coupon."
          )
      start_date = first_coupon_date or start_date
      # Adjust with settlement days
      start_date = calendar.add_business_days(
          start_date, settlement_days, roll_convention=roll_convention
      )
      if penultimate_coupon_date is None:
          backward = False
      else:
          backward = True
          end_date = end_date or penultimate_coupon_date
      # Adjust with settlement days
      end_date = calendar.add_business_days(
          end_date, settlement_days, roll_convention=roll_convention
      )
      coupon_dates = dateslib.PeriodicSchedule(
          start_date=start_date,
          end_date=end_date,
          tenor=coupon_frequency,
          roll_convention=roll_convention,
          backward=backward,
          end_of_month=end_of_month,
      ).dates()
      # Add the regular coupons
      coupon_dates = dateslib.DateTensor.concat(
          [
              start_date.expand_dims(-1),
              coupon_dates,
              end_date.expand_dims(-1),
          ],
          axis=-1,
      )
      return coupon_dates
  
imports: from typing import Optional, Tuple, Callable, Any, List, Union
  import numpy
  import tensorflow.compat.v2
  from tf_quant_finance import datetime
  from tf_quant_finance.experimental.pricing_platform.framework.core import curve_types
  from tf_quant_finance.experimental.pricing_platform.framework.core import processed_market_data
  from tf_quant_finance.experimental.pricing_platform.framework.core import types
  from tf_quant_finance.experimental.pricing_platform.framework.market_data import rate_curve
  from tf_quant_finance.experimental.pricing_platform.framework.market_data import utils
  from tf_quant_finance.experimental.pricing_platform.framework.rate_instruments import coupon_specs
  from tf_quant_finance.experimental.pricing_platform.instrument_protos import period_pb2
  from tf_quant_finance.math import pad
label_desc: Use image node_id 1 for calling a global function with example usage: _generate_schedule(start_date, end_date, coupon_frequency, calendar, roll_convention, settlement_days, end_of_month, first_coupon_date, penultimate_coupon_date) and returns: coupon_dates