module Enumerable

If the Enumerable has additional elements that aren't named in the +series+, these are not included in the result.
If the +series+ include keys that have no corresponding element in the Enumerable, these are ignored.

# => [ Person.find(1), Person.find(5), Person.find(3) ]
[ Person.find(5), Person.find(3), Person.find(1) ].in_order_of(:id, [ 1, 5, 3 ])

objects in the original enumerable.
Returns a new +Array+ where the order has been set to that provided in the +series+, based on the +key+ of the

def in_order_of(key, series)
  group_by(&key).values_at(*series).flatten(1).compact
end