pubsub.go
func WithStrictSignatureVerification(required bool) Option {
	return func(p *PubSub) error {
		p.signStrict = required
		return nil
	}
}
func WithStrictSignatureVerification(required bool) Option {
	return func(p *PubSub) error {
		p.signStrict = required
		return nil
	}
}
// WithStrictSignatureVerification is an option to enable or disable strict message signing.
// When enabled (which is the default), unsigned messages will be discarded.