|  | = Gerrit Code Review - Change metadata plugin API | 
|  |  | 
|  | This API is provided by | 
|  | link:pg-plugin-dev.html#change-metadata[plugin.changeMetadata()] and provides | 
|  | interface for customization and data updates of change metadata. | 
|  |  | 
|  | == onLabelsChanged | 
|  | `changeMetadataApi.onLabelsChanged(callback)` | 
|  |  | 
|  | .Params | 
|  | - *callback* function that's executed when labels changed on the server. | 
|  | Callback receives labels with scores applied to the change, map of the label | 
|  | names to link:rest-api-changes.html#label-info[LabelInfo] entries | 
|  |  | 
|  | .Returns | 
|  | - `GrChangeMetadataApi` for chaining. |