          +cell #[code is_parsed]
          +cell bool
          +cell A flag indicating that the document has been syntactically parsed.
  
      +row
          +cell #[code sentiment]
          +cell float
          +cell The document's positivity/negativity score, if available.
  
      +row
 
</s> remove     Doc.set_extension('is_city', default=False)
    assert Doc.has_extension('is_city')
 </s> add     Doc.set_extension('has_city', default=False)
    assert Doc.has_extension('has_city') </s> remove     Doc.set_extension('is_city', default=False)
    extension = Doc.get_extension('is_city')
 </s> add     Doc.set_extension('has_city', default=False)
    extension = Doc.get_extension('has_city')
    +row
        +cell #[code is_sentenced]
        +cell bool
        +cell
            |  A flag indicating that sentence boundaries have been applied to
            |  the document.

          +cell #[code is_parsed]
          +cell bool
          +cell A flag indicating that the document has been syntactically parsed.
  
    +row
        +cell #[code is_sentenced]
        +cell bool
        +cell
            |  A flag indicating that sentence boundaries have been applied to
            |  the document.

      +row
          +cell #[code sentiment]
          +cell float
          +cell The document's positivity/negativity score, if available.
  
      +row
keep keep keep add keep keep keep keep keep keep
 Use better examples for Doc extension methods 
website/api/doc.jade