def get_prev_sibling_tags(mention):
    """Return the HTML tag of the Mention's previous siblings.

    Previous siblings are Mentions which are at the same level in the HTML tree
    as the given mention, but are declared before the given mention. If a
    candidate is passed in, only the previous siblings of its first Mention are
    considered in the calculation.

    :param mention: The Mention to evaluate
    :rtype: list of strings
    """
    span = _to_span(mention)
    prev_sibling_tags = []
    i = _get_node(span.sentence)
    while i.getprevious() is not None:
        prev_sibling_tags.insert(0, str(i.getprevious().tag))
        i = i.getprevious()
    return prev_sibling_tags
Return the HTML tag of the Mention's previous siblings.

    Previous siblings are Mentions which are at the same level in the HTML tree
    as the given mention, but are declared before the given mention. If a
    candidate is passed in, only the previous siblings of its first Mention are
    considered in the calculation.

    :param mention: The Mention to evaluate
    :rtype: list of strings