class Ransack::Adapters::ActiveRecord::Context

def klassify(obj)
  if Class === obj && ::ActiveRecord::Base > obj
    obj
  elsif obj.respond_to? :klass
    obj.klass
  elsif obj.respond_to? :base_klass
    obj.base_klass
  else
    raise ArgumentError, "Don't know how to klassify #{obj}"
  end
end