## BaseWebExtensionColl<T> class Base class for [`TaskPaneCollection`](../taskpanecollection/), [`WebExtensionBindingC`](../webextensionbindingc/), [`WebExtensionProperty`](../webextensionpro......sets an item at the specified index. | ## Methods | Name | Description...Removes the item at the specified index from the collection. | ## Examples...