// Select the node that will be observed for mutations
var targetNode = document.getElementById('testingMutation');

// Options for the observer (which mutations to observe)
var config = { attributes: true, childList: true, characterData: true, subtree: true, attributeOldValue: true };

// Callback function to execute when mutations are observed
var callback = function(mutationsList) {
    for(var mutation of mutationsList) {
        console.log(mutation)
    }
};

// Create an observer instance linked to the callback function
var observer = new MutationObserver(callback);

// Start observing the target node for configured mutations
observer.observe(targetNode, config);