def METHOD_NAME(dirpath, filename, extension):
    """Return the release file that should contain the release name for a given a `dirpath`, `filename` and `extension`.
    :param dirpath: the file base folder
    :type dirpath: str
    :param filename: the file name without extension
    :type filename: str
    :param extension:
    :type extension: the file extension
    :return: the release file if the file exists
    :rtype: str
    """
    release_file = os.path.join(dirpath, filename + '.' + extension)
    # skip if info file doesn't exist
    if os.path.isfile(release_file):
        log.debug('Found release file {file}', {'file': release_file})
        return release_file