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: resource_group.rb
    path of file: ./repos/gitlabhq/lib/gitlab/ci/pipeline/seed/processable
    
    the code of the file until where you have to start completion: # frozen_string_literal: tru
    
            def to_resource
              return unless resource_group_key.present?

              resource_group = processable.project.resource_groups
                .safe_find_or_create_by(key: expanded_resource_group_key)

              resource_group if resource_group.persisted?
            end