# File lib/faye-rails/filter.rb, line 75
      def initialize(block, message, channel='/**', callback, direction)
        raise ArgumentError, "Block cannot be nil" unless block
        @channel = channel
        @original_message = message.dup
        @message = message
        @callback = callback
        @direction = direction

        if channel_matches?(@channel, @original_message['channel']) ||
          (subscribing? && subscription?(@channel)) ||
          (unsubscribing? && subscription?(@channel))
          instance_eval(&block)
        else
          pass
        end
      end