/**
* Runs a component's own slot-assignment collector once against a slot's CURRENT assignment, for
* a call from `firstUpdated()` alongside the component's ordinary `@slotchange` listener.
*
* happy-dom (verified through 20.14.5) never fires `slotchange` for a slot's INITIAL assignment --
* only for a later mutation to an already-connected slot. So a component that derives state (an
* options list, a selection default, an item collection, ...) exclusively from a `slotchange`
* handler collects nothing under it when the slotted children already exist before the component
* first renders -- the ordinary Lit "render only once data is ready" pattern, which slots every
* child in the same commit as the host itself. A real browser DOES fire the initial event, so
* calling the same collector from both `firstUpdated()` and `slotchange` keeps the component
* correct in both environments, provided the collector is idempotent against being run twice with
* the same assigned elements -- which a real browser firing both does on every connect. This
* helper only supplies the timing; the caller owns idempotency. `select.class.ts`'s
* `collectOptionsFromSlot` is the reference: identity-diffing the previous element set against the
* newly-read one makes a second call over an unchanged set contribute no duplicate
* selection-seeding side effect.
*
* A caller whose one-shot seeding logic must not fire on a legitimately empty result (nothing
* assigned yet, real content arriving later through its own ordinary `slotchange`) filters that
* case out of `collect` itself, or checks `slot.assignedElements(...)` before calling this helper
* at all -- this helper does not special-case emptiness.
*
* @param slot The slot to read (e.g. an `@query`-bound field, or
*   `renderRoot.querySelector('slot:not([name])')`). `null`/`undefined` is a no-op -- a component
*   whose relevant slot didn't render for the current props has nothing to collect yet.
* @param collect The component's own collection logic, given the slot directly rather than an
*   `Event` (`slotchange`'s `e.target`), so it has one calling convention from either origin.
*/
export declare function collectInitialSlotAssignment<T extends HTMLSlotElement>(slot:T|null|undefined,collect:(slot:T)=>void):void;