asyncronism with callbacks

async_with_callbacks.js

    const sum = function (num1, num2) {
        console.log(num1 + num2);
    }

    const sumNumbers = function (callback) {
        console.log('Summing numbers...');
        setTimeout(() => {
            callback(5, 10);
        }, 1000)
    }

    sumNumbers(sum);
    console.log('holi')