Source

File: wp-admin/includes/class-wp-plugin-install-list-table.php

private function order_callback( $plugin_a, $plugin_b ) {
		$orderby = $this->orderby;
		if ( ! isset( $plugin_a->$orderby, $plugin_b->$orderby ) ) {
			return 0;
		}

		$a = $plugin_a->$orderby;
		$b = $plugin_b->$orderby;

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

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