# File lib/core/container.rb, line 277
      def initialize(io, handler, container)
        @io, @handler = io, handler
        @listener = Listener.new(io, container)
        env = ENV['PN_TRACE_EVT']
        if env && ["true", "1", "yes", "on"].include?(env.downcase)
          @log_prefix = "[0x#{object_id.to_s(16)}](PN_LISTENER_"
        else
          @log_prefix = nil
        end
        dispatch(:on_open);
      end