def get_stopwords(filename):
    """Read stopword list from file.

    Assumes that the list is defined as a newline separated words. It is
    a utility in case you'd like to provide your own stopwords list.
    Assumes encoding ``utf8``.

    :param filename: Name of the file containing stopword list.
    :type filename: string
    :return: List of stopwords
    :rtype: set
    """
    stopwords = set()
    with open(filename, 'r', encoding='utf8') as fp:
        for line in fp:
            word = line.strip()
            stopwords.add(word)
    return stopwords
