# File lib/grape/dsl/inside_route.rb, line 258
      def file(value = nil)
        if value.is_a?(String)
          file_body = Grape::ServeFile::FileBody.new(value)
          @file = Grape::ServeFile::FileResponse.new(file_body)
        elsif !value.is_a?(NilClass)
          warn '[DEPRECATION] Argument as FileStreamer-like object is deprecated. Use path to file instead.'
          @file = Grape::ServeFile::FileResponse.new(value)
        else
          @file
        end
      end