| Hero         | timestamp           |

| Batman       | 2016-12-08 12:00:00 |
| Batman       | 2016-12-08 12:07:00 |
| Batman       | 2016-12-08 13:00:00 |
| Batman       | 2016-12-08 14:00:00 |
| Batman       | 2016-12-08 15:00:00 |
| Wonder Woman | 2016-12-08 10:15:00 |
| Wonder Woman | 2016-12-08 10:18:00 |
| Wonder Woman | 2016-12-08 10:25:00 |
| Wonder Woman | 2016-12-08 11:30:00 |
| Wonder Woman | 2016-12-08 11:40:00 |
| Wonder Woman | 2016-12-08 11:42:00 |
| Wonder Woman | 2016-12-08 11:45:00 |
| Wonder Woman | 2016-12-08 12:00:00 |

| Hero         | start_time          | end_time            |

| Batman       | 2016-12-08 12:00:00 | 2016-12-08 12:07:00 |
| Wonder Woman | 2016-12-08 10:15:00 | 2016-12-08 11:45:00 |

| Hero         | start_time          | end_time            |

| Batman       | 2016-12-08 13:00:00 | NULL                |
| Batman       | 2016-12-08 14:00:00 | NULL                |
...
| Batman       | 2016-12-08 12:00:00 | 2016-12-08 12:07:00 |
| Wonder Woman | 2016-12-08 10:15:00 | 2016-12-08 11:45:00 |