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: serialize_matcher.rb
    path of file: ./repos/shoulda-matchers/lib/shoulda/matchers/active_record
    
    the code of the file until where you have to start completion: module Shoulda
  module Matchers
    module ActiveRecord
      # The `serialize` matcher
    
        def serialization_valid?
          if attribute_is_serialized?
            true
          else
            @missing = "no serialized attribute called :#{@name}"
            false
          end