class_docstr: Base class for spelling correction objects. Concrete sub-classes should
  implement the ``_suggestions`` method.
class_docstr_tok: ["Base","class","for","spelling","correction","objects",".","Concrete","sub-classes","should","implement","the","``","_suggestions","``","method","."]
docstr: Low-level method that yields a series of (score, "suggestion")
  tuples.
  
  :param text: the text to check.
  :param maxdist: the maximum edit distance.
  :param prefix: require suggestions to share a prefix of this length
      with the given word.
docstr_tok: ["Low-level","method","that","yields","a","series","of","(","score",",","``","suggestion","''",")","tuples",".",":","param","text",":","the","text","to","check",".",":","param","maxdist",":","the","maximum","edit","distance",".",":","param","prefix",":","require","suggestions","to","share","a","prefix","of","this","length","with","the","given","word","."]
code: def _suggestions(self, text, maxdist, prefix):
      """
      Low-level method that yields a series of (score, "suggestion")
      tuples.
  
      :param text: the text to check.
      :param maxdist: the maximum edit distance.
      :param prefix: require suggestions to share a prefix of this length
          with the given word.
      """
  
      raise NotImplementedError
  
imports: from bisect import bisect_left
  from heapq import heappush, heapreplace
  from whoosh import highlight
  from whoosh.compat import iteritems, xrange
label_desc: Use image node_id 2 for calling the Corrector obj's underlying member method code with example usage: obj._suggestions(text, maxdist, prefix) without return types