anchor.diff:  By default, modifying the score does not change which documents match. To exclude
   documents that do not meet a certain score threshold the `min_score` parameter can be set to the desired score threshold.
   
  +[[score-functions]]
  +
   The `function_score` query provides several types of score functions.
   
  +* <<function-script-score,`script_score`>>
  +* <<function-weight,`weight`>>
  +* <<function-random,`random_score`>>
  +* <<function-field-value-factor,`field_value_factor`>>
  +* <<function-decay,decay functions>>: `gauss`, `linear`, `exp`
  +
  +[[function-script-score]]
   ==== Script score
   
   The `script_score` function allows you to wrap another query and customize
  
positive.code: 
  [source,js]
  --------------------------------------------------
  "DECAY_FUNCTION": {
      "FIELD_NAME": {
            "origin": "11, 12",
            "scale": "2km",
            "offset": "0km",
  
negative.code: "function_score": {
      "query": {},
      "boost": "boost for the whole query",
      "FUNCTION": {}, <1>
      "boost_mode":"(multiply|replace|...)"
  }
  --------------------------------------------------
  <1> See <<score-functions>> for a list of supported functions.
  
  Furthermore, several functions can be combined. In this case one can
  optionally choose to apply the function only if a document matches a
  