array element not updating in mongoose document code example

Example: mongoose wont update value in array

//Maybe notify mongooose the dataset has changed like this :

doc.markModified('pathToYourAttribute') 
//From the docs http://mongoosejs.com/docs/schematypes.html

person.anything = { x: [3, 4, { y: "changed" }] }; 
person.markModified('anything');