# File lib/twitter/request/multipart_with_file.rb, line 7
      def call(env)
        if env[:body].is_a?(Hash)
          env[:body].each do |key, value|
            if value.is_a?(File)
              env[:body][key] = Faraday::UploadIO.new(value, mime_type(value.path), value.path)
            elsif value.is_a?(Hash) && (value[:io].is_a?(IO) || value[:io].is_a?(StringIO))
              env[:body][key] = Faraday::UploadIO.new(value[:io], mime_type('.' + value[:type]), '')
            end
          end
        end
        @app.call(env)
      end