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+import toInteger from '../_lib/toInteger/index'
+import toDate from '../toDate/index'
+import getISOWeek from '../getISOWeek/index'
+import requiredArgs from '../_lib/requiredArgs/index'
+
+/**
+ * @name setISOWeek
+ * @category ISO Week Helpers
+ * @summary Set the ISO week to the given date.
+ *
+ * @description
+ * Set the ISO week to the given date, saving the weekday number.
+ *
+ * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
+ *
+ * ### v2.0.0 breaking changes:
+ *
+ * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
+ *
+ * @param {Date|Number} date - the date to be changed
+ * @param {Number} isoWeek - the ISO week of the new date
+ * @returns {Date} the new date with the ISO week set
+ * @throws {TypeError} 2 arguments required
+ *
+ * @example
+ * // Set the 53rd ISO week to 7 August 2004:
+ * const result = setISOWeek(new Date(2004, 7, 7), 53)
+ * //=> Sat Jan 01 2005 00:00:00
+ */
+export default function setISOWeek(dirtyDate: Date | number, dirtyISOWeek: number): Date {
+  requiredArgs(2, arguments)
+
+  const date = toDate(dirtyDate)
+  const isoWeek = toInteger(dirtyISOWeek)
+  const diff = getISOWeek(date) - isoWeek
+  date.setDate(date.getDate() - diff * 7)
+  return date
+}