node_modules/jszip/node_modules/core-js/library/modules/es6.object.seal.js

// 19.1.2.17 Object.seal(O)
var isObject = require('./_is-object')
  , meta     = require('./_meta').onFreeze;

require('./_object-sap')('seal', function($seal){
  return function seal(it){
    return $seal && isObject(it) ? $seal(meta(it)) : it;
  };
});