Why is the XLM-RoBERTa sometimes producing a standalone start of the word character (the special underscore with ord = 9601)
I'm using the `transformers` library 3.4.0.

The XLM-RoBERTa tokenizer produces in certain cases standalone start of the word characters. Is that intended?

For example:
```
tokenizer.tokenize('amerikanische')
['▁', 'amerikanische']
```
while 
```
tokenizer.tokenize('englische')
['▁englische']
```

Ah, I guess I figured that out. Does it happen when the training data set of the tokenizer never had this token at the beginning of a word but only inside a word?