class Hash
  def depth
    1 + values.map { |v| v.is_a?(Hash) ? v.depth : 1 }.max
  end

  def deep_symbolize_keys
    self.each_with_object({}) do |(k, v), h|
      if v.is_a?(Array)
        v = v.map do |vv|
          if vv.is_a?(Hash)
            vv.deep_symbolize_keys
          else
            vv
          end
        end
      elsif v.is_a?(Hash)
        v = v.deep_symbolize_keys
      end

      h[k.to_s.to_sym] = v
    end
  end
end