def spellcheck(self):
<EOL>raise NotImplementedError<EOL>
Return a list of (word, confidence) tuples of spelling corrections.

        Based on: Peter Norvig, "How to Write a Spelling Corrector"
        (http://norvig.com/spell-correct.html) as implemented in the pattern
        library.

        .. versionadded:: 0.6.0 (``textblob``)