bin/console in pub_grub-0.4.1 vs bin/console in pub_grub-0.4.2

@@ -1,22 +1,23 @@
 #!/usr/bin/env ruby
 
 require "bundler/setup"
 require "pub_grub"
+require "pub_grub/rubygems"
 
 source =
   PubGrub::StaticPackageSource.new do |s|
     s.add "foo", "2.0.0", deps: { "bar" => "~> 2.0" }
     s.add "foo", "1.1.0", deps: { "bar" => "~> 1.0" }
     s.add "foo", "1.0.0", deps: { "bar" => "~> 1.0" }
 
     s.add "bar", "2.0.0"
     s.add "bar", "1.0.0"
+
+    s.root deps: { "foo" => ">= 0" }
   end
 
-foo = source.get_package("foo")
-bar = source.get_package("bar")
-
+root = PubGrub::Package.root
 solver = PubGrub::VersionSolver.new(source: source)
 
 require 'irb'
 IRB.setup(__FILE__)
 workspace = IRB::WorkSpace.new(binding)