```ruby
require_relative 'analyzer'
require_relative 'dependencies_table'

require_relative 'utils'

module DeltaTest
  class Generator

    attr_reader *%i[
      current_spec_file
      table
    ]

    def setup!(_auto_teardown = true)
      return unless DeltaTest.active?

      return if @_setup
      @_setup = true

      DeltaTest.log('--- setup!')

      @analyzer = Analyzer.new
      @table    = DependenciesTable.load(DeltaTest.config.table_file_path)

      @current_spec_file = nil

      at_exit { teardown! } if _auto_teardown
    end

    def start!(spec_file)
      return unless DeltaTest.active?

      DeltaTest.log('--- start!(%s)' % spec_file)

      @current_spec_file = Utils.regulate_filepath(spec_file, DeltaTest.config.base_path).to_s
      @analyzer.start
    end

    def stop!
      return unless DeltaTest.active?

      DeltaTest.log('--- stop!')

      spec_file = @current_spec_file
      @current_spec_file = nil

      @analyzer.stop

      if spec_file
        @analyzer.related_source_files.each do |file|
          @table.add(spec_file, file)
        end
      end
    end

    def teardown!
      return unless @_setup
      return if @_teardown
      @_teardown = true

      DeltaTest.log('--- teardown!')

      @analyzer.stop
      @table.dump(DeltaTest.config.table_file_path)
    end

  end
end
```

Fix teardown! to support parallel_tests
user
```ruby
require_relative 'analyzer'
require_relative 'dependencies_table'

require_relative 'utils'

module DeltaTest
  class Generator

    attr_reader *%i[
      current_spec_file
      table
    ]

    def setup!(_auto_teardown = true)
      return unless DeltaTest.active?

      return if @_setup
      @_setup = true

      DeltaTest.log('--- setup!')

      @analyzer = Analyzer.new
      @table    = DependenciesTable.load(DeltaTest.config.table_file_path)

      @current_spec_file = nil

      hook_on_exit { teardown! } if _auto_teardown
    end

    def start!(spec_file)
      return unless DeltaTest.active?

      DeltaTest.log('--- start!(%s)' % spec_file)

      @current_spec_file = Utils.regulate_filepath(spec_file, DeltaTest.config.base_path).to_s
      @analyzer.start
    end

    def stop!
      return unless DeltaTest.active?

      DeltaTest.log('--- stop!')

      spec_file = @current_spec_file
      @current_spec_file = nil

      @analyzer.stop

      if spec_file
        @analyzer.related_source_files.each do |file|
          @table.add(spec_file, file)
        end
      end
    end

    def teardown!
      return unless @_setup
      return if @_teardown
      @_teardown = true

      DeltaTest.log('--- teardown!')

      @analyzer.stop
      @table.dump(DeltaTest.config.table_file_path)
    end


  private

    def hook_on_exit(&block)
      at_exit do
        if defined?(ParallelTests)
          break unless ParallelTests.first_process?
          ParallelTests.wait_for_other_processes_to_finish
        end

        block.call
      end
    end

  end
end
```
assistant