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: exported_relations_merger.rb
    path of file: ./repos/gitlabhq/lib/gitlab/import_export/project
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Gitlab
  module ImportExport
    module Project
      class ExportedRelationsMerger
        include Gitlab::ImportExport::CommandLineUtil

        def initialize(export_job:, shared:)
          @export_job = export_job
          @
    
        def save
          Dir.mktmpdir do |dirpath|
            export_job.relation_exports.each do |relation_export|
              relation = relation_export.relation
              upload = relation_export.upload
              filename = upload.export_file.filename

              tar_gz_full_path = File.join(dirpath, filename)
              decompress_path = File.join(dirpath, relation)
              Gitlab::PathTraversal.check_path_traversal!(tar_gz_full_path)
              Gitlab::PathTraversal.check_path_traversal!(decompress_path)

              # Download tar.gz
              download_or_copy_upload(
                upload.export_file, tar_gz_full_path, size_limit: relation_export.upload.export_file.size
              )

              # Decompress tar.gz
              mkdir_p(decompress_path)
              untar_zxf(dir: decompress_path, archive: tar_gz_full_path)
              File.delete(tar_gz_full_path)

              # Merge decompressed files into export_path
              RecursiveMergeFolders.merge(decompress_path, shared.export_path)
              FileUtils.rm_r(decompress_path)
            rescue StandardError => e
              shared.error(e)
              false
            end
          end

          shared.errors.empty?
        end