code: func NewMoveAllocationCommand(index string, shardId int, fromNode, toNode string) *MoveAllocationCommand {
  	return &MoveAllocationCommand{
  		index:    index,
  		shardId:  shardId,
  		fromNode: fromNode,
  		toNode:   toNode,
  	}
  }
docs: // NewMoveAllocationCommand creates a new MoveAllocationCommand.