anchor.diff:  
   p
       |  Finally, I often find the #[code .left_edge] and #[code right_edge]
  -    |  attributes especially useful. They give you the first and right tokens
  +    |  attributes especially useful. They give you the first and last token
       |  of the subtree. This is the easiest way to create a #[code Span] object
       |  for a syntactic phrase — a useful operation.
   
  
positive.code: +code.
      nlp = spacy.load('en')
      doc1 = nlp(u'Text I do want parsed.')
      doc2 = nlp(u'Text I don't want parsed', parser=False)
  
negative.code:     print([w.text for w in apples.rights])
      # ['on']
      assert apples.n_lefts == 2
      assert apples.n_rights == 1
  
      from spacy.symbols import nsubj
      doc = nlp(u'Credit and mortgage account holders must submit their requests within 30 days.')
      root = [w for w in doc if w.head is w][0]
      subject = list(root.lefts)[0]
      for descendant in subject.subtree:
          assert subject.is_ancestor_of(descendant)
  
      from spacy.symbols import nsubj
      doc = nlp(u'Credit and mortgage account holders must submit their requests.')
  