pub trait Signer: Sync + Send {
// Required methods
fn public_key(&self) -> &PublicKey;
fn sign<'life0, 'life1, 'life2, 'async_trait>(
&'life0 self,
data: &'life1 [u8],
sign_source: &'life2 SignatureSource
) -> Pin<Box<dyn Future<Output = BuckyResult<Signature>> + Send + 'async_trait>>
where Self: 'async_trait,
'life0: 'async_trait,
'life1: 'async_trait,
'life2: 'async_trait;
}