Two interesting test cases?

It works with my PR.

+ curl localhost:8080/query -XPOST -d '{
  debug(_uid_: 0xc1cee22c7ab32e68 ) {
      type.object.name.en
    }
  }'
+ python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   221  100   146  100    75   161k  84745 --:--:-- --:--:-- --:--:--  142k
{
    "debug": {
        "_uid_": "0xc1cee22c7ab32e68"
    },
    "server_latency": {
        "json": "26.214\u00b5s",
        "parsing": "33.284\u00b5s",
        "processing": "46.459\u00b5s",
        "total": "107.226\u00b5s"
    }
}
+ curl localhost:8080/query -XPOST -d 'mutation {
  delete {
     _uid_:0xc1cee22c7ab32e68 <type.object.name.en> "Cars" .
  }
}'
+ python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   123  100    35  100    88   3699   9301 --:--:-- --:--:-- --:--:--  9777
{
    "code": "ErrorOk",
    "message": "Done"
}
+ curl localhost:8080/query -XPOST -d '{
  debug(_uid_: 0xc1cee22c7ab32e68 ) {
      type.object.name.en
    }
+ python -m json.tool
}'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   218  100   145  100    73  30290  15249 --:--:-- --:--:-- --:--:-- 36250
{
    "debug": {
        "_uid_": "0xc1cee22c7ab32e68"
    },
    "server_latency": {
        "json": "16.408\u00b5s",
        "parsing": "30.501\u00b5s",
        "processing": "56.99\u00b5s",
        "total": "105.202\u00b5s"
    }
}
+ curl localhost:8080/query -XPOST -d 'mutation {
  set {
     _uid_:0xc1cee22c7ab32e68 <type.object.name.en> "newcar3" .
  }
+ python -m json.tool
}'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   123  100    35  100    88   3891   9785 --:--:-- --:--:-- --:--:-- 11000
{
    "code": "ErrorOk",
    "message": "Done"
}
+ curl localhost:8080/query -XPOST -d '{
  debug(_uid_: 0xc1cee22c7ab32e68 ) {
      type.object.name.en
    }
}'
+ python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   252  100   179  100    73  71657  29223 --:--:-- --:--:-- --:--:-- 89500
{
    "debug": {
        "_uid_": "0xc1cee22c7ab32e68",
        "type.object.name.en": "newcar3"
    },
    "server_latency": {
        "json": "48.689\u00b5s",
        "parsing": "92.511\u00b5s",
        "processing": "102.261\u00b5s",
        "total": "246.699\u00b5s"
    }
}
+ curl localhost:8080/query -XPOST -d 'mutation {
  delete {
     _uid_:0xc1cee22c7ab32e68 <type.object.name.en> "newcar3" .
  }
+ python -m json.tool
}'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   126  100    35  100    91   3820   9932 --:--:-- --:--:-- --:--:-- 10111
{
    "code": "ErrorOk",
    "message": "Done"
}
+ curl localhost:8080/query -XPOST -d '{
  debug(_uid_: 0xc1cee22c7ab32e68 ) {
      type.object.name.en
    }
+ python -m json.tool
}'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   218  100   145  100    73  28656  14426 --:--:-- --:--:-- --:--:-- 29000
{
    "debug": {
        "_uid_": "0xc1cee22c7ab32e68"
    },
    "server_latency": {
        "json": "52.47\u00b5s",
        "parsing": "55.531\u00b5s",
        "processing": "63.661\u00b5s",
        "total": "173.509\u00b5s"
    }
}