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: signature_detection.rb
    path of file: ./repos/zammad/lib
    
    the code of the file until where you have to start completion: # Copyright (C) 2012-2024 Zammad Foundation, https://zammad-foundation.org/

module SignatureDetection

=begin

try to detect the signature in list of articles for example

  messages = [
    {
      content: 'some content',
      content_type: 'text/plain',
    },
  ]

  signature = SignatureDetection.find_signature(messages)

returns

  signature = '...signature possible match...'

=end

  def self.find_signature(messages)
    signature_candi
    
  def self.by_user_id(user_id)
    type = Ticket::Article::Type.lookup(name: 'email')
    sender = Ticket::Article::Sender.lookup(name: 'Customer')
    tickets = Ticket.where(
      created_by_id:            user_id,
      create_article_type_id:   type.id,
      create_article_sender_id: sender.id
    ).limit(5).reorder(id: :desc)
    article_bodies = []
    tickets.each do |ticket|
      article = ticket.articles.first
      next if !article

      data = {
        content:      article.body,
        content_type: article.content_type,
      }
      article_bodies.push data
    end

    find_signature(article_bodies)
  end