class_docstr: Represents a volatility surface.
class_docstr_tok: ["Represents","a","volatility","surface","."]
docstr: Returns the valuation/settlement date.
docstr_tok: ["Returns","the","valuation\/settlement","date","."]
code: def settlement_date(self) -> types.DateTensor:
      """Returns the valuation/settlement date."""
      return self._valuation_date
  
imports: from typing import Optional, Callable
  import tensorflow.compat.v2
  from tf_quant_finance import datetime
  from tf_quant_finance import math
  from tf_quant_finance.experimental.pricing_platform.framework.core import daycount_conventions
  from tf_quant_finance.experimental.pricing_platform.framework.core import implied_volatility_type
  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 utils
label_desc: Use image node_id 3 for calling the VolatilitySurface obj's underlying member method code with example usage: obj.settlement_date() and returns: self