# Test format: BLS signature aggregation

A BLS signature aggregation combines a series of signatures into a single signature.

## Test case format

The test data is declared in a `data.yaml` file:

```yaml
input: List[BLS Signature] -- list of input BLS signatures
output: BLS Signature -- expected output, single BLS signature or empty.
```

- `BLS Signature` here is encoded as a string: hexadecimal encoding of 96 bytes (192 nibbles), prefixed with `0x`.
- No output value if the input is invalid.

## Condition

The `aggregate` handler should aggregate the signatures in the `input`, and the result should match the expected `output`.