title: LazyColumn - Items Key parameter purpose?
body: <p>Can someone explain me what's the main purpose of the <strong>'key'</strong> parameter inside items/itemsIndexed function of LazyListScope? What do we get or don't get if we specify that parameter? I'm not sure that I understand the official docs related to this parameter:</p>
  <blockquote>
  <p>key - a factory of stable and unique keys representing the item. Using
  the same key for multiple items in the list is not allowed. Type of
  the key should be saveable via Bundle on Android. If null is passed
  the position in the list will represent the key. When you specify the
  key the scroll position will be maintained based on the key, which
  means if you add/remove items before the current visible item the item
  with the given key will be kept as the first visible one.</p>
  </blockquote>