SignUserId Method
Signs the specified user Id of the current key.
Syntax
public fun signUserId(userId: String?, issuerUserId: String?)
Remarks
This method signs the UserId with the IssuerUserId.
To sign all user Ids in the current key set the UserId parameter to "*".
The key's passphrase is required for this operation and may be specified via Passphrase or through the KeyPassphrase event.