class ActionDispatch::Request::Utils

def deep_munge(hash, keys = [])
  return hash unless perform_deep_munge
  hash.each do |k, v|
    keys << k
    case v
    when Array
      v.grep(Hash) { |x| deep_munge(x, keys) }
      v.compact!
      if v.empty?
        hash[k] = nil
        ActiveSupport::Notifications.instrument("deep_munge.action_controller", keys: keys)
      end
    when Hash
      deep_munge(v, keys)
    end
    keys.pop
  end
  hash
end