anchor.diff:  [cols=">h,<9"]
   |===============================================================================
   |Description|Configure predicate to set custom vars (fields).
  -|       Type|Action
  +|       Type|Modifier
   |     Syntax|`set_predicate_vars`
   |Cardinality|0..1
   |     Module|predicate
  
positive.code: |===============================================================================
  |Description|Set the value of a HTTP request header.
  |       Type|Action
  |     Syntax|`setRequestHeader:=`
  |Cardinality|0..n
  |     Module|core
  |    Version|0.4
  
negative.code: |===============================================================================
  |Description|Set the value of an HTTP response header.
  |       Type|Action
  |     Syntax|`setResponseHeader:<name>=<value>`
  |Cardinality|0..n
  |     Module|core
  |    Version|0.4
  