// Initialize the error singleton $crm_error = CRM_Core_Error::singleton(); // Log an error message $crm_error->debug_log_message('An error occurred.'); // Display a user-friendly error message $crm_error->display_message('Sorry, an error occurred. Please try again later.');The `singleton()` method creates an instance of the CRM_Core_Error class, which can be used to log or display error messages. In the example above, `debug_log_message()` is used to log an error message to the CRM error log, while `display_message()` is used to display a user-friendly error message to the user. By using the CRM_Core_Error singleton, your code can take advantage of a centralized error management system that makes it easy to log, track, and display errors to users. This helps ensure that your CRM stays reliable and provides a good user experience.