# File lib/faraday_middleware/rack_compatible.rb, line 28
    def prepare_env(env)
      env[:request_headers].each do |name, value|
        name = name.upcase.tr('-', '_')
        name = "HTTP_#{name}" unless NonPrefixedHeaders.include? name
        env[name] = value
      end

      url = env[:url]
      env['rack.url_scheme'] = url.scheme
      env['PATH_INFO'] = url.path
      env['SERVER_PORT'] = url.respond_to?(:inferred_port) ? url.inferred_port : url.port
      env['QUERY_STRING'] = url.query
      env['REQUEST_METHOD'] = env[:method].to_s.upcase

      env['rack.errors'] ||= StringIO.new

      env
    end