anchor.diff:  Retrieves the cluster's <<alias,index aliases>>, including filter and routing
   information. The API does not return data stream aliases.
   
  -
   [[cat-alias-api-request]]
   ==== {api-request-title}
   
  -`GET /_cat/aliases/<alias>`
  +`GET _cat/aliases/<alias>`
   
  -`GET /_cat/aliases`
  +`GET _cat/aliases`
   
   [[cat-alias-api-prereqs]]
   ==== {api-prereq-title}
  
positive.code:     }
    }
  }
  --------------------------------------------------
  ////
  
  [source,console]
  --------------------------------------------------
  GET /_cat/aliases?v=true
  --------------------------------------------------
  // TEST[continued]
  
  The API returns the following response:
  
  [source,txt]
  --------------------------------------------------
  alias  index filter routing.index routing.search is_write_index
  alias1 test1 -      -            -              -
  alias2 test1 *      -            -              -
  alias3 test1 -      1            1              -
  alias4 test1 -      2            1,2            -
  --------------------------------------------------
  // TESTRESPONSE[s/[*]/[*]/ non_json]
  
  This response shows that `alias2` has configured a filter, and specific routing
  
negative.code: ==== {api-path-parms-title}
  
  `<alias>`::
  (Optional, string) Comma-separated list of aliases to retrieve. Supports
  wildcards (`*`). To retrieve all aliases, omit this parameter or use `*` or
  `_all`.
  
  [[cat-alias-api-query-params]]
  ==== {api-query-parms-title}
  