delete(k) {
        let deleted = false;
        if (this.#size !== 0) {
            const index = this.#keyMap.get(k);
            if (index !== undefined) {
                deleted = true;
                if (this.#size === 1) {
                    this.clear();
                }
                else {
                    this.#removeItemSize(index);
                    const v = this.#valList[index];
                    if (this.#isBackgroundFetch(v)) {
                        v.__abortController.abort(new Error('deleted'));
                    }
                    else if (this.#hasDispose || this.#hasDisposeAfter) {
                        if (this.#hasDispose) {
                            this.#dispose?.(v, k, 'delete');
                        }
                        if (this.#hasDisposeAfter) {
                            this.#disposed?.push([v, k, 'delete']);
                        }
                    }
                    this.#keyMap.delete(k);
                    this.#keyList[index] = undefined;
                    this.#valList[index] = undefined;
                    if (index === this.#tail) {
                        this.#tail = this.#prev[index];
                    }
                    else if (index === this.#head) {
                        this.#head = this.#next[index];
                    }
                    else {
                        const pi = this.#prev[index];
                        this.#next[pi] = this.#next[index];
                        const ni = this.#next[index];
                        this.#prev[ni] = this.#prev[index];
                    }
                    this.#size--;
                    this.#free.push(index);
                }
            }
        }
        if (this.#hasDisposeAfter && this.#disposed?.length) {
            const dt = this.#disposed;
            let task;
            while ((task = dt?.shift())) {
                this.#disposeAfter?.(...task);
            }
        }
        return deleted;
    }
Deletes a key out of the cache.
Returns true if the key was deleted, false otherwise.