Source

File: wp-includes/class-wp-recovery-mode.php

protected function is_network_plugin( $extension ) {
		if ( 'plugin' !== $extension['type'] ) {
			return false;
		}

		if ( ! is_multisite() ) {
			return false;
		}

		$network_plugins = wp_get_active_network_plugins();

		foreach ( $network_plugins as $plugin ) {
			if ( 0 === strpos( $plugin, $extension['slug'] . '/' ) ) {
				return true;
			}
		}

		return false;
	}