text: 'use strict';
  var anObject = require('../internals/an-object');
  var aFunction = require('../internals/a-function');
  var getSetIterator = require('../internals/get-set-iterator');
  
  // `Set.prototype.reduce` method
  // https://github.com/tc39/collection-methods
  require('../internals/export')({ target: 'Set', proto: true, real: true, forced: require('../internals/is-pure') }, {
    reduce: function reduce(callbackfn /* , initialValue */) {
      var set = anObject(this);
      var iterator = getSetIterator(set);
      var accumulator, step, value;
      aFunction(callbackfn);
      if (arguments.length > 1) accumulator = arguments[1];
      else {
        step = iterator.next();
        if (step.done) throw TypeError('Reduce of empty set with no initial value');
        accumulator = step.value;
      }
      while (!(step = iterator.next()).done) {
        accumulator = callbackfn(accumulator, value = step.value, value, set);
      }
      return accumulator;
    }
  });
  