fetchRemoveByKey

        fn fetchRemoveByKey(
            self: *Self,
            key: anytype,
            key_ctx: anytype,
            ctx: ByIndexContext,
            comptime removal_type: RemovalType,
        ) ?KV {
            const header = self.index_header orelse {
                // Linear scan.
                const key_hash = if (store_hash) key_ctx.hash(key) else {};
                const slice = self.entries.slice();
                const hashes_array = if (store_hash) slice.items(.hash) else {};
                const keys_array = slice.items(.key);
                for (keys_array, 0..) |*item_key, i| {
                    const hash_match = if (store_hash) hashes_array[i] == key_hash else true;
                    if (hash_match and key_ctx.eql(key, item_key.*, i)) {
                        const removed_entry: KV = .{
                            .key = keys_array[i],
                            .value = slice.items(.value)[i],
                        };
                        switch (removal_type) {
                            .swap => self.entries.swapRemove(i),
                            .ordered => self.entries.orderedRemove(i),
                        }
                        return removed_entry;
                    }
                }
                return null;
            };
            return switch (header.capacityIndexType()) {
                .u8 => self.fetchRemoveByKeyGeneric(key, key_ctx, ctx, header, u8, removal_type),
                .u16 => self.fetchRemoveByKeyGeneric(key, key_ctx, ctx, header, u16, removal_type),
                .u32 => self.fetchRemoveByKeyGeneric(key, key_ctx, ctx, header, u32, removal_type),
            };
        }