Please help do not know what am doing wrong . Below the my_plugin_widget class, add a function named my_plugin_register

<?php

    class My_Plugin_Widget extends WP_Widget {

        function my_plugin_widget() {
            parent::__construct( false, 'My Plugin Widget' );
        }

function widget( $args, $instance) { 
    extract ( $args );
    $title = apply_filters( 'widget_title', $instance[ 'title']);

}

    function update ( $new_instance, $old_instance) { 
      $instance = $old_instance;
      $instance[ 'title' ] = strip_tags($new_instance[ 'title' ]);
      return $instance;
   }                                
        function form ( $instance) { 
$title = esc_attr ($instance ['title']);
  require ('inc/widget-fields.php');
  }

    function my_plugin_register_widgets() {
     register_widgets('My_Plugin_Widgets');
    }
add_action ('widgets_init'. 'my_plugin_register_widgets' );


?>