def call(env)
      req = Rack::Request.new(env)
      status, headers, response = @app.call(env)

      config = SecureHeaders.config_for(req)
      flag_cookies!(headers, override_secure(env, config.cookies)) unless config.cookies == OPT_OUT
      headers.merge!(SecureHeaders.header_hash_for(req))
      [status, headers, response]
    end
def call(env)
      req = Rack::Request.new(env)
      status, headers, response = @app.call(env)

      config = SecureHeaders.config_for(req)
      flag_cookies!(headers, override_secure(env, config.cookies)) unless config.cookies == OPT_OUT
      headers.merge!(SecureHeaders.header_hash_for(req))
      [status, headers, response]
    end
merges the hash of headers into the current header set.