private function create_author_mapping_file( $file, $author_data ) {

		if ( touch( $file ) ) {
			$author_mapping = array();
			foreach ( $author_data as $author ) {
				$author_mapping[] = array(
					'old_user_login' => $author->user_login,
					'new_user_login' => $this->suggest_user( $author->user_login, $author->user_email ),
				);
			}
			$file_resource = fopen( $file, 'w' );
			\WP_CLI\utils\write_csv( $file_resource, $author_mapping, array( 'old_user_login', 'new_user_login' ) );
			return new WP_Error( 'author-mapping-error', sprintf( 'Please update author mapping file before continuing: %s', $file ) );
		} else {
			return new WP_Error( 'author-mapping-error', "Couldn't create author mapping file." );
		}
	}