## DataItem
```js
{
hash: SHA3, // SHA3-384
treeHash: SHA3, // random hash defined on the root of the tree,
parentHash: SHA3,
lvl: int, //the level above the tree root,
creator: SHA3, // the creator of this link for diff between sys and usr,
created: unix timestamp, // with ms,
importance: int, // the importance of the data - higher is more important - will be used to decide if unimportant data will be sacrificed for the sake of the reliability of more important data
content: byteArray || null,
deleted: bool
hashIfDeleted: SHA3
lastChecked: unix timestamp, // with ms,
readingErrors: int,
extras: {...}, // json
}
```