```ruby
module Carrierwave
  module Base64
    module MountingHelper
      module_function

      def check_for_deprecations(options)
        return unless options[:file_name].is_a?(String)

        warn(
          '[Deprecation warning] Setting `file_name` option to a string is '\
          'deprecated and will be removed in 3.0.0. If you want to keep the '\
          'existing behaviour, wrap the string in a Proc'
        )
      end

      def file_name(klass, options)
        if options[:file_name].respond_to?(:call)
          options[:file_name].call(klass)
        else
          options[:file_name]
        end.to_s
      end

      def define_writer(klass, attr, options)
        klass.send(:define_method, "#{attr}=") do |data|
          # rubocop:disable Lint/NonLocalExitFromIterator
          return if data.to_s.empty? || data == send(attr).to_s
          # rubocop:enable Lint/NonLocalExitFromIterator

          send("#{attr}_will_change!") if respond_to?("#{attr}_will_change!")

          return super(data) unless data.is_a?(String) &&
                                    data.strip.start_with?('data')

          super Carrierwave::Base64::Base64StringIO.new(
            data.strip,
            Carrierwave::Base64::MountingHelper.file_name(self, options)
          )
        end
      end
    end
  end
end
```

Fix rubocop warnings after rubocop update
user
```ruby
module Carrierwave
  module Base64
    module MountingHelper
      module_function

      def check_for_deprecations(options)
        return unless options[:file_name].is_a?(String)

        warn(
          '[Deprecation warning] Setting `file_name` option to a string is '\
          'deprecated and will be removed in 3.0.0. If you want to keep the '\
          'existing behaviour, wrap the string in a Proc'
        )
      end

      def file_name(klass, options)
        if options[:file_name].respond_to?(:call)
          options[:file_name].call(klass)
        else
          options[:file_name]
        end.to_s
      end

      def define_writer(klass, attr, options)
        klass.send(:define_method, "#{attr}=") do |data|
          # rubocop:disable Lint/NonLocalExitFromIterator
          return if data.to_s.empty? || data == send(attr).to_s

          # rubocop:enable Lint/NonLocalExitFromIterator

          send("#{attr}_will_change!") if respond_to?("#{attr}_will_change!")

          return super(data) unless data.is_a?(String) &&
                                    data.strip.start_with?('data')

          super Carrierwave::Base64::Base64StringIO.new(
            data.strip,
            Carrierwave::Base64::MountingHelper.file_name(self, options)
          )
        end
      end
    end
  end
end
```
assistant