class SimpleForm::Inputs::CollectionInput

"simple_form.no" keys. See the example locale file.
Texts can be translated using i18n in "simple_form.yes" and
collection is given. Always fallback to this boolean collection.
Default boolean collection for use with selects/radios when no

def self.boolean_collection
  i18n_cache :boolean_collection do
    [ [I18n.t(:"simple_form.yes", :default => 'Yes'), true],
      [I18n.t(:"simple_form.no", :default => 'No'), false] ]
  end
end