040000 tree bc4af3393d8357def935e3c27e1a200c1b1f1117	includes
040000 tree 7fe293356ac4e3b8d94f59b1bc6419697b616d64	set.difference
040000 tree a92eba533afebe93961836ccb53433cb3f84f92b	set.intersection
040000 tree e8787f7edb7749cc651b8b4c8dcabefa08a40fe7	set.symmetric.difference
040000 tree 350c1a874d19643a6d8806d918d79783cf341dd8	set.union