def header_name_of_wsgi_key(wsgi_key: str) -> str:
    """
    >>> header_name_of_wsgi_key('HTTP_ACCEPT_LANGUAGE')
    'Accept-Language'
    >>> header_name_of_wsgi_key('HTTP_AUTHORIZATION')
    'Authorization'

    """
    if wsgi_key.startswith('HTTP_'):
        words_for_short = {'IM', 'HTTP2', 'MD5', 'TE', 'DNT', 'ATT', 'UIDH', 'XSS'}
        return '-'.join((s if s in words_for_short else s.capitalize()) for s in wsgi_key[5:].split('_'))
    else:
        return ''