Booleans comapred strictly

Fixes #71 insight suggestions
no it does not, it just returns current element, which is:
```
return $this->buffer[$this->key];
```

according php manual:
```
Note:

Attempting to access an array key which has not been defined is the same as accessing any other undefined variable: an E_NOTICE-level error message will be issued, and the result will be NULL. 
```