What hidden property that now represent the lexical environment carry over any time you return a function from a function (closure)?.

For example

function createForEach(arr) {
let index = 0
   function inner() {
    const element = arr[index]
    index++
   return element
 }
   return inner
}

const forEach = createForEach([1,2,3])
forEach.inner() // 1
forEach.inner() // 2
console.log(forEach)