def update(self, *iterables):
_set = self._set<EOL>values = set(chain(*iterables))<EOL>if (<NUM_LIT:4> * len(values)) > len(_set):<EOL><INDENT>_list = self._list<EOL>_set.update(values)<EOL>_list.clear()<EOL>_list.update(_set)<EOL><DEDENT>else:<EOL><INDENT>_add = self.add<EOL>for value in values:<EOL><INDENT>_add(value)<EOL><DEDENT><DEDENT>return self<EOL>
Update the set, adding elements from all *iterables*.