SignUserId Method
Signs the specified user Id of the current key.
Syntax
public void signUserId(String userId, String issuerUserId);
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.