module Enumerable

# => [1, "David"]
[{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pick(:id, :name)

# => "David"
[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pick(:name)

Extract the given key from the first element in the enumerable.

def pick(*keys)
  return if none?
  if keys.many?
    keys.map { |key| first[key] }
  else
    first[keys.first]
  end
end