code: def file?(method)
        @files ||= {}
        @files[method] ||= begin
          file = @object.send(method) if @object && @object.respond_to?(method)
          file && ::Formula.file.any? { |method| file.respond_to?(method) }
        end
      end
docs: Introspection on an association to determine if a method is a file. This
   is determined by the methods ability to respond to file methods.