use DittoAttachment;
/// A representation of the events that can occur in relation to an attachment fetch.
///
/// There are three different attachment fetch events: `Completed`, `Progress`, or `Deleted`.
///
/// There will be at most one `completed` or `deleted` event per attachment fetch. There can be many
/// `progress` events delivered for each attachment fetch.
///
/// Updates relating to an attachment fetch are delivered by registering a `DittoAttachmentFetcher`
/// through a call to [`fetch_attachment`](crate::store::Store::fetch_attachment)