I have setup a project to test the capability of CodeQL，to test taint tracking ablitity

here is my project
```
https://github.com/hatface/codeql_cap_evalution
```

here is the test result
```
https://github.com/hatface/codeql_cap_evalution/blob/main/CodeQL_Capacibility_Test_Result.md
```

here is the CodeQL Query
```cpp
https://github.com/hatface/codeql_cap_evalution/blob/main/taint_cap_test.ql
```

and the case5 is failed

QUESTION：
how to fix the situation using ```isAdditionalTaintStep```