anchor.diff:  if all unmapped fields are handled as if these were default string fields. In those cases one can configure the
   `index.percolator.map_unmapped_fields_as_string` setting to `true` (default to `false`) and then if a field referred in
   a percolator query does not exist, it will be handled as a default string field, so adding the percolator query doesn't
  -fail.+fail.
  
positive.code: --------------------------------------------------
  
  .Additional supported query string options
  * `routing` - In the case the percolate queries are partitioned by a custom routing value, that routing option make sure
  that the percolate request only gets executed on the shard where the routing value is partitioned to. This means that
  the percolate request only gets executed on one shard instead of all shards. Multiple values can be specified as a
  comma separated string, in that case the request can be be executed on more than one shard.
  
negative.code: === Dedicated percolator index
  
  Percolate queries can be added to any index. Instead of adding percolate queries to the index the data resides in,
  these queries can also be added to a dedicated index. The advantage of this is that this dedicated percolator index
  can have its own index settings (For example the number of primary and replicas shards). If you choose to have a dedicated
  percolate index, you need to make sure that the mappings from the normal index are also available on the percolate index.
  Otherwise percolate queries can be parsed incorrectly.
  