adfdsf.rb

class Foo
  attr_accessor :current_session

  def initialize(current_session)
    @current_session = current_session
  end

  def foobarbaz
    # Baz.send(:include, Bar)
    Baz.include(Bar)
  end
end

class Baz
end

module Bar
  def foobar
    @current_session
    # 'foobar'
  end
end

puts Foo.new('current_session').foobarbaz.new.foobar # 'foobar'