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: qa_changes.rb
    path of file: ./repos/gitlabhq/qa/qa/tools/ci
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "pathname"

module QA
  module Tools
    module Ci
      # Determine specific qa specs or paths to execute based on changes
      class QaChanges
        include Helpers

        QA_PATTERN
    
        def qa_tests
          return if mr_diff.empty? || dependency_changes
          return if only_spec_changes? && mr_diff.all? { |change| change[:deleted_file] }

          if only_spec_changes?
            return mr_diff
              .reject { |change| change[:deleted_file] }
              .map { |change| change[:path].delete_prefix("qa/") } # make paths relative to qa directory
              .join(" ")
          end