Cannot get statistics on data returned by integration

[Vladdy65]

Not sure if this is a bug or one is simply not meant to be able to add a climate.xxxx entity to a dashboard Statistics Graph. I can't test as I only have Heatmiser climate entities. None of the Heatmiser integration climate entities appear in the "Add a statistic" options list. A Home Assistant message leads one to the following link if expected data source is not listed: https://www.home-assistant.io/more-info/statistics/. The latter claims this may be a bug, and suggests one open an issue with the author of the integration, linking them to this link: https://developers.home-assistant.io/docs/core/entity/sensor#long-term-statistics. So here I am.

[MindrustUK]

Acknowledging this, investigation required when I get some time.