anchor.diff:  
   [source,js]
   --------------------------------------------------
  -$ curl -XGET 'http://localhost:9200/_cluster/allocation/explain' -d '{
  +GET /_cluster/allocation/explain
  +{
     "index": "myindex",
     "shard": 0,
     "primary": false,
     "current_node": "nodeA"                         <1>
  -}'
  ---------------------------------------------------
  +}
  +--------------------------------------------------
  +// CONSOLE
  +// TEST[skip:no way of knowing the current_node]
   <1> The node where shard 0 currently has a replica on
   
   You can also have Elasticsearch explain the allocation of the first unassigned
  
positive.code: 
  [source,js]
  --------------------------------------------------
  $ curl -XGET 'http://localhost:9200/_cluster/allocation/explain?include_disk_info=true'
  --------------------------------------------------
  
  Additionally, if you would like to include all decisions that were factored into the final
  decision, the `include_yes_decisions` parameter will return all decisions for each node:
  
  [source,js]
  --------------------------------------------------
  $ curl -XGET 'http://localhost:9200/_cluster/allocation/explain?include_yes_decisions=true'
  --------------------------------------------------
  
  The default value for `include_yes_decisions` is `false`, which will only
  include the `no` decisions in the response.  This is generally what you would
  
negative.code: [float]
  === Explain API Request
  
  To explain the allocation of a shard, first an index should exist:
  
  [source,js]
  --------------------------------------------------
  PUT /myindex
  --------------------------------------------------
  // TESTSETUP
  
  And then the allocation for shards of that index can be explained:
  
  [source,js]
  --------------------------------------------------
  GET /_cluster/allocation/explain
  {
    "index": "myindex",
    "shard": 0,
    "primary": true
  }
  --------------------------------------------------
  // CONSOLE
  
  Specify the `index` and `shard` id of the shard you would like an explanation
  for, as well as the `primary` flag to indicate whether to explain the primary
  