Modify BootstrapAggregator to make it compatible with other type of namedtuple Score.
Modify BootstrapAggregator to make it compatible with other type of namedtuple Score.

PiperOrigin-RevId: 236951361

google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research,google-research/google-research