Retrieve the secret value of this object synchronously.
Each retrievable object has a single secret which might be a password or some other secret binary value.
This method may block indefinitely and should not be used in user interface threads.
optional cancellation object
the secret value which should be released with secret.value.Value.unref, or null
Retrieve the secret value of this object synchronously.
Each retrievable object has a single secret which might be a password or some other secret binary value.
This method may block indefinitely and should not be used in user interface threads.