Prevent deletion of specific user

prevent_delete_user.php

// MY_USER_ID
define( 'MY_USER_ID', 7 );

/**
 * Delete User action, checks for our defined user id
 * 
 */
function themename_delete_user( $id ){
	if ( $id == MY_USER_ID ) {
		wp_die( 'You cannot delete this user' );
	}
}
add_action( 'delete_user', 'themename_delete_user' );

/**
 * Remove MY_USER_ID from user table
 * 
 */
function themename_pre_user_query( $query ){
	global $pagenow, $wpdb;
	if ( is_admin() && $pagenow === 'users.php' && get_current_user_id() != MY_USER_ID ){
		$query->query_where = $query->query_where . " AND $wpdb->users.ID != " . MY_USER_ID. " ";
	}
}
add_filter( 'pre_user_query', 'themename_pre_user_query' );