text: const axios = require('axios');
  
  const main = {
      add: (num1, num2) => (num1 + num2),
      isNull: () => (null),
      isUndefined: () => (undefined),
      checkValue: (x) => x,
      createUser: () => {
          const user = {
              firstName: "Shabuktagin"
          };
          user['lastName'] = "Khan";
          return user;
      },
      fetchUser: () => axios
          .get('https://jsonplaceholder.typicode.com/users/1')
          .then(response => response.data)
          .catch(err => console.log(err)),
      stringReverse: (string) => string.split('').reverse().join(''),
  }
  
  module.exports = main;