WP_DEBUG: PHP notices with WP 5.2

Activating the plugin causes:

PHP Notice: The called constructor method for WP_Widget in C3M_My_Favs is deprecated since version 4.3.0! Use

__construct()

instead. in /wp-includes/functions.php on line 4503
PHP Stack trace:
PHP 1. {main}() /wp-admin/plugins.php:0
PHP 2. require_once() /wp-admin/plugins.php:10
PHP 3. require_once() /wp-admin/admin.php:34
PHP 4. require_once() /wp-load.php:37
PHP 5. require_once() /wp-config.php:141
PHP 6. do_action($tag = *uninitialized*, $arg = *uninitialized*) /wp-settings.php:525
PHP 7. WP_Hook->do_action($args = *uninitialized*) /wp-includes/plugin.php:465
PHP 8. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) /wp-includes/class-wp-hook.php:310
PHP 9. wp_widgets_init(*uninitialized*) /wp-includes/class-wp-hook.php:286
PHP 10. do_action($tag = *uninitialized*, $arg = *uninitialized*) /wp-includes/widgets.php:1715
PHP 11. WP_Hook->do_action($args = *uninitialized*) /wp-includes/plugin.php:465
PHP 12. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) /wp-includes/class-wp-hook.php:310
PHP 13. c3m_register(*uninitialized*) /wp-includes/class-wp-hook.php:286
PHP 14. register_widget($widget = *uninitialized*) /wp-content/plugins/favorite-plugins-widget/favorite-plugins-widget.php:267
PHP 15. WP_Widget_Factory->register($widget = *uninitialized*) /wp-includes/widgets.php:115
PHP 16. C3M_My_Favs->__construct() /wp-includes/class-wp-widget-factory.php:100
PHP 17. C3M_My_Favs->WP_Widget($id_base = *uninitialized*, $name = *uninitialized*, $widget_options = *uninitialized*, $control_options = *uninitialized*) /wp-content/plugins/favorite-plugins-widget/favorite-plugins-widget.php:107
PHP 18. _deprecated_constructor($class = *uninitialized*, $version = *uninitialized*, $parent_class = *uninitialized*) /wp-includes/class-wp-widget.php:192
PHP 19. trigger_error(*uninitialized*) /wp-includes/functions.php:4503

PHP Warning: Cannot modify header information – headers already sent by (output started at /wp-includes/functions.php:4503) in /wp-admin/includes/misc.php on line 1196
PHP Stack trace:
PHP 1. {main}() /wp-admin/plugins.php:0
PHP 2. require_once() /wp-admin/plugins.php:10
PHP 3. do_action($tag = *uninitialized*, $arg = *uninitialized*) /wp-admin/admin.php:169
PHP 4. WP_Hook->do_action($args = *uninitialized*) /wp-includes/plugin.php:465
PHP 5. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) /wp-includes/class-wp-hook.php:310
PHP 6. wp_admin_headers(*uninitialized*) /wp-includes/class-wp-hook.php:286
PHP 7. header(*uninitialized*) /wp-admin/includes/misc.php:1196
PHP Notice: The called constructor method for WP_Widget in C3M_My_Favs is deprecated since version 4.3.0! Use

__construct()

instead. in /wp-includes/functions.php on line 4503
PHP Stack trace:
PHP 1. {main}() /index.php:0
PHP 2. require() /index.php:17
PHP 3. require_once() /wp-blog-header.php:13
PHP 4. require_once() /wp-load.php:37
PHP 5. require_once() /wp-config.php:141
PHP 6. do_action($tag = *uninitialized*, $arg = *uninitialized*) /wp-settings.php:525
PHP 7. WP_Hook->do_action($args = *uninitialized*) /wp-includes/plugin.php:465
PHP 8. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) /wp-includes/class-wp-hook.php:310
PHP 9. wp_widgets_init(*uninitialized*) /wp-includes/class-wp-hook.php:286
PHP 10. do_action($tag = *uninitialized*, $arg = *uninitialized*) /wp-includes/widgets.php:1715
PHP 11. WP_Hook->do_action($args = *uninitialized*) /wp-includes/plugin.php:465
PHP 12. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) /wp-includes/class-wp-hook.php:310
PHP 13. c3m_register(*uninitialized*) /wp-includes/class-wp-hook.php:286
PHP 14. register_widget($widget = *uninitialized*) /wp-content/plugins/favorite-plugins-widget/favorite-plugins-widget.php:267
PHP 15. WP_Widget_Factory->register($widget = *uninitialized*) /wp-includes/widgets.php:115
PHP 16. C3M_My_Favs->__construct() /wp-includes/class-wp-widget-factory.php:100
PHP 17. C3M_My_Favs->WP_Widget($id_base = *uninitialized*, $name = *uninitialized*, $widget_options = *uninitialized*, $control_options = *uninitialized*) /wp-content/plugins/favorite-plugins-widget/favorite-plugins-widget.php:107
PHP 18. _deprecated_constructor($class = *uninitialized*, $version = *uninitialized*, $parent_class = *uninitialized*) /wp-includes/class-wp-widget.php:192
PHP 19. trigger_error(*uninitialized*) /wp-includes/functions.php:4503