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: password_hash_test.rb
    path of file: ./repos/openstreetmap-website/test/lib
    
    the code of the file until where you have to start completion: require "test_helper"

class PasswordHashTest < ActiveSupport::TestCase
  def test_md5_without_salt
    assert PasswordHash.check("5f4dcc3b5aa765d61d8327deb882cf99", nil, "password")
    assert_not PasswordHash.check("5f4dcc3b5aa765d61d8327deb882cf99", nil, "wrong")
    assert PasswordHash.upgrade?("5f4dcc3b5aa765d61d8327deb882cf99", nil)
  end

  def test_md5_wit
    
  def test_default
    hash1, salt1 = PasswordHash.create("password")
    hash2, salt2 = PasswordHash.create("password")
    assert_not_equal hash1, hash2
    assert_nil salt1
    assert_nil salt2
    assert PasswordHash.check(hash1, salt1, "password")
    assert_not PasswordHash.check(hash1, salt1, "wrong")
    assert PasswordHash.check(hash2, salt2, "password")
    assert_not PasswordHash.check(hash2, salt2, "wrong")
    assert_not PasswordHash.upgrade?(hash1, salt1)
    assert_not PasswordHash.upgrade?(hash2, salt2)
  end