def find_ensured(name)
      downcased_name = name.irc_downcase(@bot.irc.isupport["CASEMAPPING"])
      @mutex.synchronize do
        @cache[downcased_name] ||= Channel.new(name, @bot)
      end
    end
def find_ensured(name)
      downcased_name = name.irc_downcase(@bot.irc.isupport["CASEMAPPING"])
      @mutex.synchronize do
        @cache[downcased_name] ||= Channel.new(name, @bot)
      end
    end
Finds or creates a channel.

 @param [String] name name of a channel
 @return [Channel]
 @see Helpers#Channel