# File lib/faraday/connection.rb, line 246
    def default_parallel_manager
      @default_parallel_manager ||= begin
        handler = @builder.handlers.detect do |h|
          h.klass.respond_to?(:supports_parallel?) and h.klass.supports_parallel?
        end

        if handler
          handler.klass.setup_parallel_manager
        elsif block_given?
          yield
        end
      end
    end