You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: runner.rb
    path of file: ./repos/truffleruby/lib/patches/launchy/detect
    
    the code of the file until where you have to start completion: # truffleruby_primitives: true

# Copyright (c) 2007-2013 Jeremy Hinegardner
#
#
    
    def self.detect
      host_os_family = Launchy::Detect::HostOsFamily.detect
      ruby_engine    = Launchy::Detect::RubyEngine.detect

      return Windows.new if host_os_family.windows?

      if ruby_engine.jruby? || ruby_engine.truffleruby? then
        # This is a bit misnamed now. But the point is the Jruby runner class avoids using `fork'.
        return Jruby.new
      end