anchor.diff:  This is useful for highlighting the entire contents of a document or field.
   
   
  -[[highlighter-internal]]
  -==== How highlighters work internally
  -
  -To learn how highlighters work internally check the document
  -<<highlighter-internal-work, How highlighters work internally>>.+include::highlighters-internal.asciidoc[]
  
positive.code: boundaries.  The `boundary_max_scan` setting controls how far to scan for
  boundary characters. Only valid for the `fvh` highlighter.
  `sentence`::: Break highlighted fragments at the next sentence boundary, as
  determined by Java's 
  https://docs.oracle.com/javase/8/docs/api/java/text/BreakIterator.html[BreakIterator].
  You can specify the locale to use with `boundary_scanner_locale`.
  +
  
negative.code: it doesn't require reanalyzing the text to be highlighted. It also requires less
  disk space than using `term_vectors`.
  
  * Term vectors. If `term_vector` information is provided by setting
  `term_vector` to `with_positions_offsets` in the mapping, the `unified`
  highlighter automatically uses the `term_vector` to highlight the field.
  It's fast especially for large fields (> `1MB`) and for highlighting multi-term queries like
  