class KPM::BaseInstaller

def extract_jruby_jar_version(jruby_jar)
  selected_entries = Zip::File.open(jruby_jar) do |zip_file|
    zip_file.select do |entry|
      entry.name == 'META-INF/maven/org.kill-bill.billing/killbill-platform-osgi-bundles-jruby/pom.properties'
    end
  end
  if selected_entries && selected_entries.size == 1
    zip_entry = selected_entries[0]
    content = zip_entry.get_input_stream.read
    return content.split("\n").select { |e| e.start_with?('version') }[0].split('=')[1]
  end
  nil
end