What is timepivot?

The https://docs.loganalytics.io/docs/Language-Reference/Tabular-operators/render-operator mentions a timepivot renderer as a visualization, and near the end of the document it even uses it as an exampe for the by operator

• By is an optional list of columns that is used by some visualizations (e.g. timepivot) to control which "axis" is driven by which column in the data.

however when I try to use it on analytics.applicationinsights.io I get the error message 

 FAILED TO CREATE VISUALIZATION
We currently don't support 'timepivot' visualization type.

Am I using it incorrectly or is this a feature that is in the documentation but is not yet/no longer supported by the analytics site?