Assert a bag is equal to another.
Pseudocode: (a_collection ⇒ a_bag) = (b_collection ⇒ b_bag)
use assertables::*; let a = [1, 1]; let b = [1, 1]; assert_bag_eq!(a, b);
assert_bag_eq
assert_bag_eq_as_result
debug_assert_bag_eq