question: the index the search failed on . concode_field_sep String reason concode_elem_sep ShardSearchFailure[] EMPTY_ARRAY concode_elem_sep SearchShardTarget shardTarget concode_elem_sep Throwable cause concode_elem_sep RestStatus status concode_field_sep String reason concode_elem_sep void writeTo concode_elem_sep void readFrom concode_elem_sep XContentBuilder toXContent concode_elem_sep int shardId concode_elem_sep String toString concode_elem_sep SearchShardTarget shard concode_elem_sep Throwable getCause concode_elem_sep RestStatus status concode_elem_sep ShardSearchFailure readShardSearchFailure
target: String function ( ) { if ( shardTarget != null ) { return shardTarget . index ( ) ; } return null ; }