instance method validate_transformation

# File activestorage/app/models/active_storage/variation.rb, line 96
    def validate_transformation(name, argument)
      method_name = name.to_s.gsub("-","_")

      unless ActiveStorage.supported_image_processing_methods.any? { |method| method_name == method }
        raise UnsupportedImageProcessingMethod, <<~ERROR.squish
          One or more of the provided transformation methods is not supported.
        ERROR
      end

      if argument.present?
        if argument.is_a?(String) || argument.is_a?(Symbol)
          validate_arg_string(argument)
        elsif argument.is_a?(Array)
          validate_arg_array(argument)
        elsif argument.is_a?(Hash)
          validate_arg_hash(argument)
        end
      end
    end