private function install_one( $args, $assoc_args ) {
		$theme          = array_shift( $args );
		$language_codes = (array) $args;
		$count          = count( $language_codes );

		$available = $this->get_installed_languages( $theme );

		$successes = 0;
		$errors    = 0;
		$skips     = 0;
		foreach ( $language_codes as $language_code ) {

			if ( in_array( $language_code, $available, true ) ) {
				\WP_CLI::log( "Language '{$language_code}' already installed." );
				$skips++;
			} else {
				$response = $this->download_language_pack( $language_code, $theme );

				if ( is_wp_error( $response ) ) {
					\WP_CLI::warning( $response );
					\WP_CLI::log( "Language '{$language_code}' not installed." );

					// Skip if translation is not yet available.
					if ( 'not_found' === $response->get_error_code() ) {
						$skips++;
					} else {
						$errors++;
					}
				} else {
					\WP_CLI::log( "Language '{$language_code}' installed." );
					$successes++;
				}
			}
		}

		\WP_CLI\Utils\report_batch_operation_results( 'language', 'install', $count, $successes, $errors, $skips );
	}