Parse a <release> object

def _parse_tree(self, node):
        """ Parse a <release> object """
        if 'timestamp' in node.attrib:
            self.timestamp = int(node.attrib['timestamp'])
        if 'date' in node.attrib:
            dt = dateutil.parser.parse(node.attrib['date'])
            self.timestamp = int(dt.strftime("%s"))
        if 'urgency' in node.attrib:
            self.urgency = node.attrib['urgency']
        if 'version' in node.attrib:
            self.version = node.attrib['version']
            # fix up hex value
            if self.version.startswith('0x'):
                self.version = str(int(self.version[2:], 16))
        for c3 in node:
            if c3.tag == 'description':
                self.description = _parse_desc(c3)
            if c3.tag == 'size':
                if 'type' not in c3.attrib:
                    continue
                if c3.attrib['type'] == 'installed':
                    self.size_installed = int(c3.text)
                if c3.attrib['type'] == 'download':
                    self.size_download = int(c3.text)
            elif c3.tag == 'checksum':
                csum = Checksum()
                csum._parse_tree(c3)
                self.add_checksum(csum)