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: assessment_user_datum.rb
    path of file: ./repos/Autolab/app/models
    
    the code of the file until where you have to start completion: # Read https://github.com/autolab/autolab-src/wiki/Caching
require
    
  def submission_status
    if latest_submission
      :submitted
    elsif past_end_at?
      :not_submitted
    else
      :not_yet_submitted
    end