function initializeClient(client) {
  if (client.init) {
    client.init();
    // TODO v8: Remove this fallback
    // eslint-disable-next-line deprecation/deprecation
  } else if (client.setupIntegrations) {
    // eslint-disable-next-line deprecation/deprecation
    client.setupIntegrations();
  }
}
Initialize the client for the current scope.
Make sure to call this after `setCurrentClient()`.