.append(", runtime: ")
                .append(System.getProperty("java.home", "<unknown runtime>"))
                .append(ls);
        version.append("Default locale: ")
                .append(Locale.getDefault())
                .append(", platform encoding: ")
                .append(System.getProperty("file.encoding", "<unknown encoding>"))
                .append(ls);
        version.append("OS name: \"")

   * testing {@link Object#equals} because more than one sample instances are needed for testing
   * inequality.
   */
  protected final <T> void setDefault(Class<T> type, T value) {
    tester.setDefault(type, value);
  }

  /**
   * Sets two distinct values for {@code type}. These values can be used for both null pointer
   * testing and equals testing.
   *
   * @since 17.0

  @get:JvmName("proxySelector")
  val proxySelector: ProxySelector =
    when {
      // Defer calls to ProxySelector.getDefault() because it can throw a SecurityException.
      builder.proxy != null -> NullProxySelector
      else -> builder.proxySelector ?: ProxySelector.getDefault() ?: NullProxySelector
    }

  @get:JvmName("proxyAuthenticator")
  val proxyAuthenticator: Authenticator =

  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.setDefault(BigInteger.class, ONE);
    tester.setDefault(int.class, 1);
    tester.setDefault(long.class, 1L);
    tester.testAllPublicStaticMethods(BigIntegerMath.class);
  }

  @GwtIncompatible // String.format
  @FormatMethod

            String username = System.getenv("MVNW_USERNAME");
            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
            Authenticator.setDefault(new Authenticator() {
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(username, password);
                }

        }
      }
    }
  }

  public void testNulls() {
    NullPointerTester tester =
        new NullPointerTester()
            .setDefault(SleepingStopwatch.class, stopwatch)
            .setDefault(int.class, 1)
            .setDefault(double.class, 1.0d);
    tester.testStaticMethods(RateLimiter.class, Visibility.PACKAGE);
    tester.testInstanceMethods(RateLimiter.create(5.0, stopwatch), Visibility.PACKAGE);

        }
      }
    }
  }

  public void testNulls() {
    NullPointerTester tester =
        new NullPointerTester()
            .setDefault(SleepingStopwatch.class, stopwatch)
            .setDefault(int.class, 1)
            .setDefault(double.class, 1.0d);
    tester.testStaticMethods(RateLimiter.class, Visibility.PACKAGE);
    tester.testInstanceMethods(RateLimiter.create(5.0, stopwatch), Visibility.PACKAGE);

  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testSuppliersNullChecks() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))
        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testSuppliersNullChecks() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))
        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

          .put("HmacSHA512", SHA512_KEY, Hashing.hmacSha512(SHA512_KEY))
          .buildOrThrow();

  public void testNulls() {
    NullPointerTester tester =
        new NullPointerTester().setDefault(String.class, "HmacMD5").setDefault(Key.class, MD5_KEY);
    tester.testAllPublicConstructors(MacHashFunction.class);
    tester.testAllPublicInstanceMethods(new MacHashFunction("HmacMD5", MD5_KEY, "toString"));
  }