class Middleman::Extension

def expose_methods
  (self.class.exposed_to_application || {}).each do |k, v|
    app.define_singleton_method(k, &method(v))
  end
  (self.class.exposed_to_config || {}).each do |k, v|
    app.config_context.define_singleton_method(k, &method(v))
  end
  (self.class.defined_helpers || []).each do |m|
    app.template_context_class.send(:include, m)
  end
end