code: def dates(self, typ, light=None):
          '''
          Args:
              typ: type of calibration to look for. See .coeffs.keys() for all types available
              light (Optional[str]): restrict to calibrations, done given light source
  
          Returns:
              list: All calibration dates available for given typ
          '''
          try:
              d = self._getDate(typ, light)
              return [self._toDateStr(c[0]) for c in d]
          except KeyError:
              return [f dates(self, typ, light=None):
          '''
          Args:
              typ: type of calibration to look for. See .coeffs.keys() for all types available
              light (Optional[str]): restrict to calibrations, done given light source
  
          Returns:
              list: All calibration dates available for given typ
          '''
          try:
              d = self._getDate(typ, light)
              return [self._toDateStr(c[0]) for c in d]
          except KeyError:
              return []
docs: Args:
              typ: type of calibration to look for. See .coeffs.keys() for all types available
              light (Optional[str]): restrict to calibrations, done given light source
  
          Returns:
              list: All calibration dates available for given typ