anchor.diff:  [[search-shards]]
   === Search Shards API
   
  -The search shards api returns the indices and shards that a search request would
  -be executed against. This can give useful feedback for working out issues or
  -planning optimizations with routing and shard preferences. When filtered aliases
  -are used, the filter is returned as part of the `indices` section [5.1.0] Added in 5.1.0.
  -
  -The `index` may be a single value, or comma-separated.
  -
  -[float]
  -==== Usage
  -
  -Full example:
  +Returns the indices and shards that a search request would be executed against.
   
   [source,js]
   --------------------------------------------------
  
positive.code: // TESTRESPONSE[s/bU_KLGJISbW0RejwnwDPKw/$body.shards.3.0.allocation_id.id/]
  // TESTRESPONSE[s/DMs7_giNSwmdqVukF7UydA/$body.shards.4.0.allocation_id.id/]
  
  And specifying the same request, this time with a routing value:
  
  [source,js]
  --------------------------------------------------
  
negative.code: // TESTRESPONSE[s/0TvkCyF7TAmM1wHP4a42-A/$body.shards.1.0.allocation_id.id/]
  // TESTRESPONSE[s/fMju3hd1QHWmWrIgFnI4Ww/$body.shards.0.0.allocation_id.id/]
  
  The search will only be executed against two of the shards, because outing 
  values have been specified.
  