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: yaml_serializer.rb
    path of file: ./repos/ruby/lib/bundler
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Bundler
  # A stub yaml serializer that can handle only hashes and strings (as of now).
  module YAMLSerializer
    module_function

    def dump(hash)
      yaml = String.new("---")
      yaml << dump_hash(hash)
    end

    d
    
    def load(str)
      res = {}
      stack = [res]
      last_hash = nil
      last_empty_key = nil
      str.split(/\r?\n/) do |line|
        if match = HASH_REGEX.match(line)
          indent, key, quote, val = match.captures
          val = strip_comment(val)

          convert_to_backward_compatible_key!(key)
          depth = indent.size / 2
          if quote.empty? && val.empty?
            new_hash = {}
            stack[depth][key] = new_hash
            stack[depth + 1] = new_hash
            last_empty_key = key
            last_hash = stack[depth]
          else
            val = [] if val == "[]" # empty array
            stack[depth][key] = val
          end
        elsif match = ARRAY_REGEX.match(line)
          _, val = match.captures
          val = strip_comment(val)

          last_hash[last_empty_key] = [] unless last_hash[last_empty_key].is_a?(Array)

          last_hash[last_empty_key].push(val)
        end