protected function get_all_languages( $slug = null ) {
		require_once ABSPATH . '/wp-admin/includes/translation-install.php';
		require ABSPATH . WPINC . '/version.php'; // Include an unmodified $wp_version

		$args = array(
			'version' => $wp_version,
		);

		if ( $slug ) {
			$args['slug'] = $slug;

			if ( 'plugins' === $this->obj_type ) {
				$plugins         = get_plugins( '/' . $slug );
				$plugin_data     = array_shift( $plugins );
				$args['version'] = $plugin_data['Version'];
			} elseif ( 'themes' === $this->obj_type ) {
				$theme_data      = wp_get_theme( $slug );
				$args['version'] = $theme_data['Version'];
			}
		}

		$response = translations_api( $this->obj_type, $args );

		if ( is_wp_error( $response ) ) {
			WP_CLI::error( $response );
		}

		$translations = ! empty( $response['translations'] ) ? $response['translations'] : array();

		$en_us = array(
			'language'     => 'en_US',
			'english_name' => 'English (United States)',
			'native_name'  => 'English (United States)',
			'updated'      => '',
		);

		$translations[] = $en_us;

		uasort( $translations, array( $this, 'sort_translations_callback' ) );

		return $translations;
	}