nDate.prototype.yearOfWeek` is an accessor property whose set accessor function is *undefined*.
        Its get accessor function performs the following steps:
      </p>
      <emu-alg>
        1. Let _plainDate_ be the *this* value.
        1. Perform ? RequireInternalSlot(_plainDate_, [[InitializedTemporalDate]]).
        1. Let _result_ be CalendarISOToDate(_plainDate_.[[Calendar]], _plainDate_.[[ISODate]]).[[WeekOfYear]].[[Year]].
        1. If _result_ is *undefined*, return *undefined*.
        1. Re