## BaseWebExtensionColl class Base class for [TaskPaneCollection](../taskpanecollection/), [WebExtensionBindingC](../webextensionbindingc/), [WebExtensionProperty](../webextensionproperty/) and [We......sets an item at the specified index. | | [idx_set](./idx_set/)(int32_t...sets an item at the specified index. | | [Remove](./remove/)(int32_t)...