Elasticsearch: 2 children with the same ID, but with different parents

child_same_id.sh

curl -XDELETE localhost:9200/test
curl -XPUT localhost:9200/test
curl -XPUT localhost:9200/test/parent/1 -d '{"foo": "p_foo1"}'
curl -XPUT localhost:9200/test/parent/2 -d '{"foo": "p_foo1"}'
curl -XPUT localhost:9200/test/child/_mapping -d '{
    "child": {
        "_parent": {
            "type": "parent"
        }
    }
}'
curl -XPUT localhost:9200/test/child/id1?parent=1 -d '{"foo": "c1"}'
curl -XPUT localhost:9200/test/child/id1?parent=2 -d '{"foo": "c2"}'
curl -XPOST localhost:9200/test/_refresh
curl -XPOST localhost:9200/test/child/_search?pretty -d '{"fields": ["_parent","_source"]}'
curl -XGET localhost:9200/test/child/id1?routing=1
curl -XGET localhost:9200/test/child/id1?routing=2