```ruby
class TestingGround
  class TreeSampler
    RESOLUTION_LENGTH_LOW = 365

    def self.sample(networks, resolution = nil, nodes = nil)
      Hash[networks.each_pair.map do |carrier, graph|
        NetworkCache::LoadSetter.set(graph, nodes) do |node|
          downsample(node.load, resolution || :low)
        end

        [carrier, GraphToTree.convert(graph)]
      end]
    end

    def self.downsample(node_load, resolution)
      size = (node_load.length / RESOLUTION_LENGTH_LOW).floor

      if resolution.to_sym == :low && size > 0
        node_load.each_slice(size).map { |loads| loads.max_by(&:abs) }
      else
        node_load
      end
    end
  end
end
```

Change TreeSampler to be a module
user
```ruby
class TestingGround
  module TreeSampler
    RESOLUTION_LENGTH_LOW = 365

    module_function

    def sample(networks, resolution = nil, nodes = nil)
      Hash[networks.each_pair.map do |carrier, graph|
        NetworkCache::LoadSetter.set(graph, nodes) do |node|
          downsample(node.load, resolution || :low)
        end

        [carrier, GraphToTree.convert(graph)]
      end]
    end

    def downsample(node_load, resolution)
      size = (node_load.length / RESOLUTION_LENGTH_LOW).floor

      if resolution.to_sym == :low && size > 0
        node_load.each_slice(size).map { |loads| loads.max_by(&:abs) }
      else
        node_load
      end
    end
  end
end
```
assistant