I am trying to tokenize the following sentence type: 

`"The item at issue is no. 3553."`

Every tokenizer I've tried so far returns the following (including a Punkt tokenizer trained on my corpus):

`[["the", "item", "at", "issue", "is", "no."], ["3553."]]`

Adding a "no" abbreviation to the tokenizer would be a problem for sentences ending in "no."