Table
| Extension | 0..* | |
| Extension.id | string | 0..1 |
| Extension.extension | Extension | 0..* |
| Extension.url | uri | 1..1 |
| Extension.valueReference | Reference(dm-device-metric) | 1..1 |
| Extension | 0..* | |
| Extension.id | string | 0..1 |
| Extension.extension | Extension | 0..* |
| Extension.url | uri | 1..1 |
| Extension.valueReference | Reference(dm-device-metric) | 1..1 |