task2.js

finction memoize (fn) {
  const cache = {};
  return function (...args) {
    let stringifiedArgs = JSON.stringify(args);
    if (cache[stringifiedArgs]) {
      return cache[stringifiedArgs];
    }
    const result = fn(...arguments);
    cache[stringifiedArgs] = result;
    return result;
  };
};

const getBondsDataFn = async ({date, isins}) => {
  const result = await http.post({
    url: `/bonds/${date}`,
    body: isins
  });
  
  return result;
};

const getBondsData = memoize(getBondsDataFn);

getBondsData({   date: '20180120',    isins: ['XS0971721963', 'RU000A0JU4L3']  });