Downloads the file from the url to the destination folder.
            If no destination folder is specified, the default one is used.
            (The default downloads folder = "./downloaded_files")

def download_file(self, file_url, destination_folder=None):
        """ Downloads the file from the url to the destination folder.
            If no destination folder is specified, the default one is used.
            (The default downloads folder = "./downloaded_files") """
        if not destination_folder:
            destination_folder = constants.Files.DOWNLOADS_FOLDER
        page_utils._download_file_to(file_url, destination_folder)