public static Properties copyProperties(Properties properties) {
        final Properties copyProperties = new Properties();
        // guard against modification/removal of keys in the given properties (MNG-5670, MNG-6053, MNG-6105)
        synchronized (properties) {
            copyProperties.putAll(properties);
        }
        return copyProperties;
    }

  }

  public void testFinalizeClassHasNoNestedClasses() throws Exception {
    // Ensure that the Finalizer class has no nested classes.
    // See https://code.google.com/p/guava-libraries/issues/detail?id=1505
    assertEquals(Collections.emptyList(), Arrays.asList(Finalizer.class.getDeclaredClasses()));
  }

  }

  public void testFinalizeClassHasNoNestedClasses() throws Exception {
    // Ensure that the Finalizer class has no nested classes.
    // See https://code.google.com/p/guava-libraries/issues/detail?id=1505
    assertEquals(Collections.emptyList(), Arrays.asList(Finalizer.class.getDeclaredClasses()));
  }

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are: