WP_MS_Themes_List_Table::get_views

	 * @global string $orderby
	 * @global string $order
	 * @param array $theme_a
	 * @param array $theme_b
	 * @return int
	 */
	public function _order_callback( $theme_a, $theme_b ) {
		global $orderby, $order;

		$a = $theme_a[ $orderby ];
		$b = $theme_b[ $orderby ];

		if ( $a == $b ) {
			return 0;
		}

		if ( 'DESC' === $order ) {
			return ( $a < $b ) ? 1 : -1;
		} else {
			return ( $a < $b ) ? -1 : 1;
		}
	}

	/**
	 */
	public function no_items() {
		if ( $this->has_items ) {
			_e( 'No themes found.' );
		} else {
			_e( 'No themes are currently available.' );
		}
	}

	/**
	 * @return array
	 */
	public function get_columns() {
		$columns = array(
			'cb'          => '<input type="checkbox" />',
			'name'        => __( 'Theme' ),
			'description' => __( 'Description' ),
		);

		if ( $this->show_autoupdates ) {
			$columns['auto-updates'] = __( 'Automatic Updates' );
		}

		return $columns;
	}

	/**
	 * @return array
	 */
	protected function get_sortable_columns() {
		return array(
			'name' => 'name',
		);
	}

	/**
	 * Gets the name of the primary column.
	 *
	 * @since 4.3.0
	 *
	 * @return string Unalterable name of the primary column name, in this case, 'name'.
	 */
	protected function get_primary_column_name() {
		return 'name';
	}

	/**
	 * @global array $totals
	 * @global string $status
	 * @return array
	 */