## sampleRUM(checkpoint, data) log RUM if part of the sample. This is an internal API and should not be called directly by projects. The collection service validates and rejects samples with unknown `checkpoint` values and implausible `source` and `target` value. **Kind**: global function | Param | Type | Description | | --- | --- | --- | | checkpoint | string | identifies the checkpoint in funnel | | data | Object | additional data for RUM sample | | data.source | string | DOM node that is the source of a checkpoint event, identified by #id or .classname | | data.target | string | subject of the checkpoint event, for instance the href of a link, or a search term |