A base class with no predefined methods that tries to behave like Builder‘s BlankSlate in Ruby 1.9. In Ruby pre-1.9, this is actually the Builder::BlankSlate class.

Ruby 1.9 introduces BasicObject which differs slightly from Builder‘s BlankSlate that has been used so far. ActiveSupport::BasicObject provides a barebones base class that emulates Builder::BlankSlate while still relying on Ruby 1.9‘s BasicObject in Ruby 1.9.