anchor.diff:                                  :text-document (make-text-document-identifier buffer)
                                   :options (make-instance
                                             'protocol:formatting-options
  -                                          :tab-size (variable-value 'tab-width)
  -                                          :insert-spaces (not (variable-value 'indent-tabs-mode))
  +                                          :tab-size (variable-value 'tab-width :buffer buffer)
  +                                          :insert-spaces (not (variable-value 'indent-tabs-mode :buffer buffer))
                                             :trim-trailing-whitespace t
                                             :insert-final-newline t
                                             :trim-final-newlines t))))))))
  
positive.code:    (text-document/document-symbol (current-buffer))))
  
  ;;; formatting
  (defun provide-formatting-p (workspace)
    (handler-case (protocol:server-capabilities-document-formatting-provider
                   (workspace-server-capabilities workspace))
  
negative.code: - [ ] documentLink resolve
  - [ ] documentColor
  - [ ] colorPresentation
  - [X] formatting
  - [ ] rangeFormatting
  - [ ] onTypeFormatting
  - [ ] rename
  