Display custom taxonomies in taxonomy lists in Twenty Sixteen child theme

functions.php

<?php
/**
 * Prints HTML with category and tags for current post.
 * Augmented from the Twenty Sixteen original, found in inc/template-tags.php
 */
function twentysixteen_entry_taxonomies() {

	// Display Class taxonomy when available
	$tax_class_title = '<span class="tax-title">' . __( 'Class:', 'wpcampus' ) . '</span> ';
	$class_list = get_the_term_list( $post->ID, 'class', $tax_class_title, _x( ', ', 'Used between list items, there is a space after the comma.', 'wpcampus' ) );
	if ( $class_list && ( 'lecture' === get_post_type() ) ) {
		echo '<span class="cat-links">' . $class_list . '</span>';
	}

	// Display Year taxonomy when available
	$tax_year_title = '<span class="tax-title">' . __( 'Year:', 'wpcampus' ) . '</span> ';
	$year_list = get_the_term_list( $post->ID, 'year', $tax_year_title, _x( ', ', 'Used between list items, there is a space after the comma.', 'wpcampus' ) );
	if ( $year_list && ( 'lecture' === get_post_type() ) ) {
		echo '<span class="cat-links">' . $year_list . '</span>';
	}

	$categories_list = get_the_category_list( _x( ', ', 'Used between list items, there is a space after the comma.', 'wpcampus' ) );
	if ( $categories_list && twentysixteen_categorized_blog() ) {
		if ( 'lecture' === get_post_type() ) {
			printf( '<span class="cat-links"><span class="tax-title">%1$s</span> %2$s</span>',
				_x( 'Categories: ', 'Used before category names.', 'wpcampus' ),
				$categories_list
			);
		} else {
			printf( '<span class="cat-links"><span class="screen-reader-text">%1$s </span>%2$s</span>',
				_x( 'Categories', 'Used before category names.', 'wpcampus' ),
				$categories_list
			);
		}
	}

	$tags_list = get_the_tag_list( '', _x( ', ', 'Used between list items, there is a space after the comma.', 'wpcampus' ) );
	if ( $tags_list ) {
		if ( 'lecture' === get_post_type() ) {
			printf( '<span class="tags-links"><span class="tax-title">%1$s </span>%2$s</span>',
				_x( 'Tags: ', 'Used before tag names.', 'wpcampus' ),
				$tags_list
			);
		} else {
			printf( '<span class="tags-links"><span class="screen-reader-text">%1$s </span>%2$s</span>',
				_x( 'Tags', 'Used before tag names.', 'wpcampus' ),
				$tags_list
			);
		}
	}
}