'Generate new URLs based on original_url.
:param original_url: The original url that has to be modified in
order to trigger errors in the remote application.'

def _generate_urls(self, original_url):

    special_chars = ['|', '~']
    filename = original_url.get_file_name()
    if ((filename != '') and ('.' in filename)):
        splitted_filename = filename.split('.')
        extension = splitted_filename[(-1):][0]
        name = '.'.join(splitted_filename[0:(-1)])
        for char in special_chars:
            new_filename = (((name + char) + '.') + extension)
            new_url = original_url.url_join(new_filename)
            (yield new_url)
