def METHOD_NAME(self):
    project = self.create_project()
    event1 = self.store_event(
        data={
            "event_id": "a" * 32,
            "timestamp": iso_format(before_now(seconds=1)),
            "fingerprint": ["group-1"],
            "extra": {"foo": "bar"},
        },
        project_id=project.id,
    )
    group1 = event1.group
    event2 = self.store_event(
        data={
            "event_id": "b" * 32,
            "timestamp": iso_format(before_now(seconds=1)),
            "fingerprint": ["group-2"],
            "extra": {"foo": "baz"},
        },
        project_id=project.id,
    )
    group2 = event2.group
    with self.tasks():
        eventstream_state = eventstream.backend.start_merge(project.id, [group1.id], group2.id)
        merge_groups([group1.id], group2.id)
        eventstream.backend.end_merge(eventstream_state)
    assert not Group.objects.filter(id=group1.id).exists()
    event1 = eventstore.backend.get_event_by_id(project.id, event1.event_id)
    assert event1.group_id == group2.id
    assert event1.data["extra"]["foo"] == "bar"
    event2 = eventstore.backend.get_event_by_id(project.id, event2.event_id)
    assert event2.group_id == group2.id
    assert event2.data["extra"]["foo"] == "baz"