convert_parameters_to_hashes

# File actionpack/lib/action_controller/metal/strong_parameters.rb, line 1156
      def convert_parameters_to_hashes(value, using, &block)
        case value
        when Array
          value.map { |v| convert_parameters_to_hashes(v, using) }
        when Hash
          transformed = value.transform_values do |v|
            convert_parameters_to_hashes(v, using)
          end
          (block_given? ? transformed.to_h(&block) : transformed).with_indifferent_access
        when Parameters
          value.send(using)
        else
          value
        end
      end