@property<EOL><INDENT>def next_group_id(self) -> int:<DEDENT>
ids: typing.Set[int] = set()<EOL>for group in chain(self._blue_coa.groups, self._red_coa.groups):  <EOL><INDENT>id_ = group.group_id<EOL>if id_ in ids:<EOL><INDENT>raise IndexError(group.group_name)<EOL><DEDENT>ids.add(id_)<EOL><DEDENT>return max(ids) + <NUM_LIT:1><EOL>
Returns: next free GroupId