def join(key = nil)
      if key.nil? and self.key != true
        key = self.key
      end
      @bot.irc.send "JOIN #{[@name, key].compact.join(" ")}"
    end
def join(key = nil)
      if key.nil? and self.key != true
        key = self.key
      end
      @bot.irc.send "JOIN #{[@name, key].compact.join(" ")}"
    end
Joins the channel

 @param [String] key the channel key, if any. If none is
   specified but @key is set, @key will be used
 @return [void]