    # File lib/rack/multipart/parser.rb, line 12
          def self.create(env)
            return DUMMY unless env['CONTENT_TYPE'] =~ MULTIPART

            io = env['rack.input']
            io.rewind

            content_length = env['CONTENT_LENGTH']
            content_length = content_length.to_i if content_length

            tempfile = env['rack.multipart.tempfile_factory'] ||
              lambda { |filename, content_type| Tempfile.new(["RackMultipart", ::File.extname(filename)]) }
            bufsize = env['rack.multipart.buffer_size'] || BUFSIZE

            new($1, io, content_length, env, tempfile, bufsize)
          end