def log_url (self, url_data):
        """Write one node."""
        node = self.get_node(url_data)
        if node:
            self.writeln(u"  node [")
            self.writeln(u"    id     %d" % node["id"])
            self.writeln(u'    label  "%s"' % node["label"])
            if self.has_part("realurl"):
                self.writeln(u'    url  "%s"' % node["url"])
            if node["dltime"] >= 0 and self.has_part("dltime"):
                self.writeln(u"    dltime %d" % node["dltime"])
            if node["size"] >= 0 and self.has_part("dlsize"):
                self.writeln(u"    size %d" % node["size"])
            if node["checktime"] and self.has_part("checktime"):
                self.writeln(u"    checktime %d" % node["checktime"])
            if self.has_part("extern"):
                self.writeln(u"    extern %d" % node["extern"])
            self.writeln(u"  ]")