+ def notification_token
+ sha256 = Digest::SHA256.new
+ sha256 << Rails.application.key_generator.generate_key("openstreetmap/message")
+ sha256 << id.to_s
+ Base64.urlsafe_encode64(sha256.digest)[0, 8]
+ end
+
+ def notify_recipient?
+ !muted?
+ end
+
+ def unmute
+ update(:muted => false)
+ end
+
+ private
+
+ def set_muted
+ self.muted ||= UserMute.active?(:owner => recipient, :subject => sender)