his* value.
        1. Perform ? RequireInternalSlot(_plainDate_, [[InitializedTemporalDate]]).
        1. Let _result_ be CalendarISOToDate(_plainDate_.[[Calendar]], _plainDate_.[[ISODate]]).[[WeekOfYear]].[[Week]].
        1. If _result_ is *undefined*, return *undefined*.
        1. Return ùîΩ(_result_).
      </emu-alg>
    </emu-clause>

    <emu-clause id="sec-get-temporal.plaindate.prototype.yearofweek">
      <h1>get Temporal.PlainDate.prototype.yearOfWeek</h1>
      <p>
        `Temporal.Plai