You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: full_quote_header_spec.rb
    path of file: ./repos/zammad/spec/system/ticket/update
    
    the code of the file until where you have to start completion: # Copyright (C) 2012-2
    
    def confirm_style
      case style
      when :forward
        citation_text.match?(%r{Subject(.+)\nDate(.+)})
      when :reply
        citation_text.match?(%r{^On(.+)wrote:$})
      end