def get(type, hash)
      dir = directory(type, hash)
      return unless dir
      dir.files.get(key_component(type, hash))
    end
def get(type, hash)
      dir = directory(type, hash)
      return unless dir
      dir.files.get(key_component(type, hash))
    end
Retrieves a file from the store.

    layer.get("documents", hash)