anchor.diff:  // TEST[setup:twitter]
   
   The above will execute the search against the `twitter` index for all the
  -requests that don't define an index, and the last one will be executed
  -against the `twitter2` index.
  +requests that don't define an `index` target in the request body. The last
  +search will be executed against the `twitter2` index.
   
   The `search_type` can be set in a similar manner to globally apply to
   all search requests.
  
positive.code: [[search-multi-search-api-request]]
  ==== {api-request-title}
  
  `GET /<index>/_msearch`
  
  
  [[search-multi-search-api-desc]]
  
negative.code: 
  `index`:::
  (Optional, string or array of strings)
  Data streams, indices, and index aliases to search. Wildcard (`*`) expressions
  are supported. You can specify multiple targets as an array.
  +
  If this parameter is not specified, the `<target>` request path parameter
  is used as a fallback.
  
  `preference`:::
  (Optional, string)
  