# File lib/bundler.rb, line 97
    def setup(*groups)
      # Return if all groups are already loaded
      return @setup if defined?(@setup) && @setup

      definition.validate_runtime!

      SharedHelpers.print_major_deprecations!

      if groups.empty?
        # Load all groups, but only once
        @setup = load.setup
      else
        load.setup(*groups)
      end
    end