bump phpstan levet to 6 (#115)

improve and fix tuple return types (#109)

fix colletion methods docblocks (#99)

implement indexOf for Sequence (#96)

* implement indexOf for Sequence

* fix phpstan

Implement findFirst for collection (#94)

Fix stream iterate factory (#91)

Allow to correctly compare other values (#89)

Allow to define value mapper for toMap collector (#87)

* Remove to array casts

* Allow to define value mapper for toMap collector

Implement disjoint method for traversable (#86)

Implement removeAll for Set (#85)

* Implement removeAll for Set

* Add more tests