options.go
func Mute(b bool) Option {
	return Option(func(c *config) {
		c.Client.Muted = b
	})
}
func Mute(b bool) Option {
	return Option(func(c *config) {
		c.Client.Muted = b
	})
}
// Mute sets whether the Client is muted. All methods of a muted Client do
// nothing and return immedialtly.
//
// This option can be used in Client.Clone() only if the parent Client is not
// muted. The clones of a muted Client are always muted.