// GetField resolves a merklepath against the object and returns// either a primitive (e.g. string, int, etc), a link (type CID),// or another Node.//// If a Node is returned, it will be a unrooted node -- that is,// it can be used to view the fields below it, but since it was not// originally stored as a full node, you cannot immediately take// a link to it for embedding in other objects (you'd have to make// a new RootNode with the same content first, then store that).GetField(path[]string)(interface{},error)