def do_target(t: str) -> None:
    if (t not in self.targets):
        return self._gen_exception('set_property', f'TARGET {t} not found', tline)
    tgt = self.targets[t]
    if (identifier not in tgt.properties):
        tgt.properties[identifier] = []
    if append:
        tgt.properties[identifier] += value
    else:
        tgt.properties[identifier] = value
def do_target(t: str) -> None:
    if (t not in self.targets):
        return self._gen_exception('set_property', f'TARGET {t} not found', tline)
    tgt = self.targets[t]
    if (identifier not in tgt.properties):
        tgt.properties[identifier] = []
    if append:
        tgt.properties[identifier] += value
    else:
        tgt.properties[identifier] = value