"use strict";
  
  Object.defineProperty(exports, "__esModule", {
      value: true
  });
  exports.default = concat;
  function concat(eachfn, arr, fn, callback) {
      var result = [];
      eachfn(arr, function (x, index, cb) {
          fn(x, function (err, y) {
              result = result.concat(y || []);
              cb(err);
          });
      }, function (err) {
          callback(err, result);
      });
  }
  module.exports = exports["default"];