class Puma::Configuration

def rack_builder
  # Load bundler now if we can so that we can pickup rack from
  # a Gemfile
  if @puma_bundler_pruned
    begin
      require 'bundler/setup'
    rescue LoadError
    end
  end
  begin
    require 'rack'
    require 'rack/builder'
    ::Rack::Builder
  rescue LoadError
    require_relative 'rack/builder'
    Puma::Rack::Builder
  end
end