Apply method for Ruby's Object, as (maybe?) more clean alternative to long method chain.

Ruby apply

Object.class_eval do
  def apply(&block)
    instance_eval(&block) if block_given?
  end
end

arr = []
arr.apply do
  push [1, 2]
  p self # => [[1, 2]]
  push [3, 4]
  p self # => [[1, 2], [3, 4]]
  flatten
end
p arr # => [1, 2, 3, 4]