question: get the id of the shard which allocation should be canceled concode_field_sep String node concode_elem_sep String NAME concode_elem_sep ShardId shardId concode_elem_sep boolean allowPrimary concode_field_sep void writeTo concode_elem_sep String node concode_elem_sep CancelAllocationCommand readFrom concode_elem_sep void toXContent concode_elem_sep String name concode_elem_sep CancelAllocationCommand fromXContent concode_elem_sep boolean allowPrimary concode_elem_sep RerouteExplanation execute
target: ShardId function ( ) { return this . shardId ; }