class Grape::Util::Lazy::ValueEnumerable

def [](key)
  if @value_hash[key].nil?
    Value.new(nil).reached_by(access_keys, key)
  else
    @value_hash[key].reached_by(access_keys, key)
  end
end

def []=(key, value)
  @value_hash[key] = case value
                     when Hash
                       ValueHash.new(value)
                     when Array
                       ValueArray.new(value)
                     else
                       Value.new(value)
                     end
end

def fetch(access_keys)
  fetched_keys = access_keys.dup
  value = self[fetched_keys.shift]
  fetched_keys.any? ? value.fetch(fetched_keys) : value
end