```ruby title="Ruby"
require 'kreuzberg'

class WordCountProcessor
  def call(result)
    return result if result['content'].empty?
    word_count = result['content'].split.length
    result['metadata'] ||= {}
    result['metadata']['word_count'] = word_count
    result
  end
end

processor = WordCountProcessor.new
Kreuzberg.register_post_processor('word_count', processor, 10)

config = Kreuzberg::ExtractionConfig.new(
  postprocessor: { enabled: true }
)

result = Kreuzberg.extract_file_sync('document.pdf', config: config)
puts "Words: #{result.metadata['word_count']}"
```