curl 'http://localhost:8000/form-params' --data 'param1=value1' --data 'param2=' --data 'param3=a%3Db' --data 'param4=a%253db'
curl 'http://localhost:8000/form-params' -H 'Content-Type: application/x-www-form-urlencoded' --data 'param1=value1&param2=&param3=a%3db&param4=a%253db'