Cheap exceptions, opinionated error handling

[alexeypetrushin]

It is mentioned that `ErrorCode` covers many different errors, including HTTP 
statuses, like 404.
    
    
    proc canOverflow() {.raises: ErrorCode.} =
      echo a + b
    
    
    Run

So, if a person reading a library method - `proc canOverflow() {.raises: 
ErrorCode.}` he may assume that any sort of exception, including that HTTP 404 
could be thrown?