I need to calculate fees for each transaction in block.

I retrieve raw block data and use `bitcoinjs-lib` library to decode it to `Block` object:

```
const block = Bitcoin.Block.fromHex(data.rawblock);

```

It has an array of `Transaction` objects. However, while these transactions' `outs` have `value`s, `ins` have only `hash` and `script`.

How should I process this data so I can get total in and out amounts and calculate transaction fee?