Returns {name: Enum}

def _load_enums(root):
    """Returns {name: Enum}"""
    out = collections.OrderedDict()
    for elem in root.findall('enums/enum'):
        name = elem.attrib['name']
        value = elem.attrib['value']
        comment = elem.get('comment')
        out[name] = Enum(name, value, comment)
    return out