Extracts a list of versions that an xml element references. Returns
    a [ 1 ] list if there isn't a versions attribute.

def _get_xml_version(element):
    """Extracts a list of versions that an xml element references. Returns
    a [ 1 ] list if there isn't a versions attribute."""
    if "versions" in element.attrib:
        result = [ int(v) for v in re.split(",\s*", element.attrib["versions"]) ]
    else:
        result = [ 1 ]

    return result