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<b>Warning</b>:  session_start(): Session cannot be started after headers have already been sent in <b>/home/tvrreohg/public_html/manga.php</b> on line <b>13</b><br />
﻿'use strict';

module.exports = function union(object) {
  const collection = JSON.parse(JSON.stringify(this.items));

  Object.keys(object).forEach((prop) => {
    if (this.items[prop] === undefined) {
      collection[prop] = object[prop];
    }
  });

  return new this.constructor(collection);
};