# File lib/rack/utils.rb, line 446
446:         def initialize(path, content_type = "text/plain", binary = false)
447:           raise "#{path} file does not exist" unless ::File.exist?(path)
448:           @content_type = content_type
449:           @original_filename = ::File.basename(path)
450:           @tempfile = Tempfile.new(@original_filename)
451:           @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
452:           @tempfile.binmode if binary
453:           FileUtils.copy_file(path, @tempfile.path)
454:         end