Custom page template with no sidebar for Twenty Sixteen child theme

functions.php

<?php
/**
 * Adds custom classes to the array of body classes.
 *
 * @param array $classes Classes for the body element.
 * @return array (Maybe) filtered body classes.
 */
function wpcampus_body_classes( $classes ) {
    // Adds a class of no-sidebar to custom no-sidebar page template.
    if ( is_page_template('page-no-sidebar.php') ) {
        $classes[] = 'no-sidebar';
    }

    return $classes;
}
add_filter( 'body_class', 'wpcampus_body_classes' );
?>

page-no-sidebar.php

<?php
/**
 * Template Name: Page with no sidebar
 *
 * The template for displaying pages without the sidebar
 *
 * This is the template that displays all pages by default.
 * Please note that this is the WordPress construct of pages and that
 * other "pages" on your WordPress site will use a different template.
 *
 * @package WordPress
 * @subpackage Twenty_Sixteen
 * @since Twenty Sixteen 1.0
 */

get_header(); ?>

<div id="primary" class="content-area">
	<main id="main" class="site-main" role="main">
		<?php
		// Start the loop.
		while ( have_posts() ) : the_post();

			// Include the page content template.
			get_template_part( 'template-parts/content', 'page' );

			// If comments are open or we have at least one comment, load up the comment template.
			if ( comments_open() || get_comments_number() ) {
				comments_template();
			}

			// End of the loop.
		endwhile;
		?>

	</main><!-- .site-main -->

</div><!-- .content-area -->

<?php get_footer(); ?>
?>