040000 tree b1cfc65195c0d261689490ae4feb11af1db9ca57	includes
040000 tree 70ba6151fa22e06b848b74e114b76a17fc3d6867	set.difference
040000 tree 68843e810d72df19c186d7a8135d990e437aa61f	set.intersection
040000 tree 49027d56302f97adeef3f9ef67440c639f7ee582	set.symmetric.difference
040000 tree 081f3e3178b0d9716f32bf6e5fde093cd652d829	set.union