foreach ( $post_types as $post_type ) {
			if ( ! isset( $post_type_dates[ $post_type ] ) ) { // If we hadn't seen post type before. R.
				$post_type_dates = null;
				break;
			}
		}

		if ( is_null( $post_type_dates ) ) {

			$post_type_dates = [];
			$post_type_names = WPSEO_Post_Type::get_accessible_post_types();

			if ( ! empty( $post_type_names ) ) {
				$post_statuses = array_map( 'esc_sql', self::get_post_statuses() );
				$replacements  = array_merge(
					[
						'post_type',
						'post_modified_gmt',
						'date',
						$wpdb->posts,
						'post_status',
					],
					$post_statuses,
					[ 'post_type' ],
					array_keys( $post_type_names ),
					[
						'post_type',
						'date',
					]
				);

				//phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- We need to use a direct query here.
				//phpcs:disable WordPress.DB.DirectDatabaseQuery.NoCaching -- Reason: No relevant caches.
				$dates = $wpdb->get_results(
					//phpcs:disable WordPress.DB.PreparedSQLPlaceholders -- %i placeholder is still not recognized.
					$wpdb->prepare(
						'
					SELECT %i, MAX(%i) AS %i
					FROM %i
					WHERE %i IN (' . implode( ', ', array_fill( 0, count( $post_statuses ), '%s' ) ) . ')
						AND %i IN (' . implode( ', ', array_fill( 0, count( $post_type_names ), '%s' ) ) . ')
					GROUP BY %i
					ORDER BY %i DESC
				',
						$replacements
					)
				);

				foreach ( $dates as $obj ) {
					$post_type_dates[ $obj->post_type ] = $obj->date;
				}
			}
		}

		$dates = array_intersect_key( $post_type_dates, array_flip( $post_types ) );

		if ( count( $dates ) > 0 ) {
			if ( $return_all ) {
				return $dates;
			}

			return max( $dates );
		}

		return false;
	}

	/**
	 * Get the modification date for the last modified post in the post type.
	 *
	 * @param array $post_types Post types to get the last modification date for.
	 *
	 * @return string
	 */
	public function get_last_modified( $post_types ) {
		return YoastSEO()->helpers->date->format( self::get_last_modified_gmt( $post_types ) );
	}

	/**
	 * Get the maximum number of entries per XML sitemap.
	 *
	 * @return int The maximum number of entries.
	 */
	protected function get_entries_per_page() {
		/**
		 * Filter the maximum number of entries per XML sitemap.
		 *
		 * After changing the output of the filter, make sure that you disable and enable the
		 * sitemaps to make sure the value is picked up for the sitemap cache.
		 *
		 * @param int $entries The maximum number of entries per XML sitemap.
		 */
		$entries = (int) apply_filters( 'wpseo_sitemap_entries_per_page', 1000 );

		return $entries;
	}

	/**
	 * Get post statuses for post_type or the root sitemap.
	 *
	 * @since 10.2
	 *
	 * @param string $type Provide a type for a post_type sitemap, SITEMAP_INDEX_TYPE for the root sitemap.
	 *
	 * @return array List of post statuses.
	 */
	public static function get_post_statuses( $type = self::SITEMAP_INDEX_TYPE ) {
		/**
		 * Filter post status list for sitemap query for the post type.
		 *
		 * @param array  $post_statuses Post status list, defaults to array( 'publish' ).
		 * @param string $type          Post type or SITEMAP_INDEX_TYPE.
		 */
		$post_statuses = apply_filters( 'wpseo_sitemap_post_statuses', [ 'publish' ], $type );

		if ( ! is_array( $post_statuses ) || empty( $post_statuses ) ) {
			$post_statuses = [ 'publish' ];
		}

		if ( ( $type === self::SITEMAP_INDEX_TYPE || $type === 'attachment' )
			&& ! in_array( 'inherit', $post_statuses, true )
		) {
			$post_statuses[] = 'inherit';
		}

		return $post_statuses;
	}

	/**
	 * Sends all the required HTTP Headers.
	 *
	 * @return void
	 */
	private function send_headers() {
		if ( headers_sent() ) {
			return;
		}

		$headers = [
			$this->http_protocol . ' 200 OK' => 200,
			// Prevent the search engines from indexing the XML Sitemap.
			'X-Robots-Tag: noindex, follow'  => '',
			'Content-Type: text/xml; charset=' . esc_attr( $this->renderer->get_output_charset() ) => '',
		];

		/**
		 * Filter the HTTP headers we send before an XML sitemap.
		 *
		 * @param array  $headers The HTTP headers we're going to send out.
		 */
		$headers = apply_filters( 'wpseo_sitemap_http_headers', $headers );

		foreach ( $headers as $header => $status ) {
			if ( is_numeric( $status ) ) {
				header( $header, true, $status );
				continue;
			}
			header( $header, true );
		}
	}
}
<br />
<b>Fatal error</b>:  Uncaught Error: Class 'WPSEO_Sitemaps' not found in /home/deltakeprico/public_html/wp-content/plugins/wordpress-seo/wp-seo-main.php:355
Stack trace:
#0 /home/deltakeprico/public_html/wp-includes/class-wp-hook.php(324): wpseo_init('')
#1 /home/deltakeprico/public_html/wp-includes/class-wp-hook.php(348): WP_Hook-&gt;apply_filters(NULL, Array)
#2 /home/deltakeprico/public_html/wp-includes/plugin.php(517): WP_Hook-&gt;do_action(Array)
#3 /home/deltakeprico/public_html/wp-settings.php(559): do_action('plugins_loaded')
#4 /home/deltakeprico/public_html/wp-config.php(90): require_once('/home/deltakepr...')
#5 /home/deltakeprico/public_html/wp-load.php(50): require_once('/home/deltakepr...')
#6 /home/deltakeprico/public_html/wp-blog-header.php(13): require_once('/home/deltakepr...')
#7 /home/deltakeprico/public_html/index.php(17): require('/home/deltakepr...')
#8 {main}
  thrown in <b>/home/deltakeprico/public_html/wp-content/plugins/wordpress-seo/wp-seo-main.php</b> on line <b>355</b><br />