hunk.code_window:   })
     it('does not mutate original date', function() {
       var date = new Date('2014-09-02T11:55:00')
       startOfHour(date)
  
hunk.labels: keep keep keep replace keep
hunk.after_edit:     var date = new Date(2014, 8 /* Sep */, 2, 11, 55)
  
hunk.file_path: src/__tests__/start_of_hour_test.js
hunk.type: replace
file: /**
   * Returns last day of a year for given date. Date will be in local timezone.
   * @param {date|string} dirtyDate
   * @returns {date}
   */
  var lastDayOfYear = function(dirtyDate) {
    var date = new Date(dirtyDate)
    var year = date.getFullYear()
    date.setHours(0, 0, 0, 0)
    date.setFullYear(year + 1, 0, 0)
    return date
  }
  
  module.exports = lastDayOfYear
  
  