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: project_setting_spec.rb
    path of file: ./repos/gitlabhq/spec/models
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require 's
    
  def valid_target_platform_combinations
    target_platforms = described_class::ALLOWED_TARGET_PLATFORMS

    0.upto(target_platforms.size).flat_map do |n|
      target_platforms.permutation(n).to_a
    end
  end