class method self.digest

# File actionview/lib/action_view/digestor.rb, line 16
      def digest(name:, format: nil, finder:, dependencies: nil)
        if dependencies.nil? || dependencies.empty?
          cache_key = "#{name}.#{format}"
        else
          dependencies_suffix = dependencies.flatten.tap(&:compact!).join(".")
          cache_key = "#{name}.#{format}.#{dependencies_suffix}"
        end

        # this is a correctly done double-checked locking idiom
        # (Concurrent::Map's lookups have volatile semantics)
        finder.digest_cache[cache_key] || @@digest_mutex.synchronize do
          finder.digest_cache.fetch(cache_key) do # re-check under lock
            path = TemplatePath.parse(name)
            root = tree(path.to_s, finder, path.partial?)
            dependencies.each do |injected_dep|
              root.children << Injected.new(injected_dep, nil, nil)
            end if dependencies
            finder.digest_cache[cache_key] = root.digest(finder)
          end
        end
      end