Checks a drill-down against the schema of the run it expands. A level must
be a column of the schema, one that can be grouped and compared
(isDrilldownLevelType), and
not an earlier level again, all in any case (foldColumnName). A saved
aggregation must name a column of the schema, once, and be null or a
function its type offers (getDrilldownAggregations).
Checks a drill-down against the schema of the run it expands. A level must be a column of the schema, one that can be grouped and compared (
isDrilldownLevelType), and not an earlier level again, all in any case (foldColumnName). A saved aggregation must name a column of the schema, once, and benullor a function its type offers (getDrilldownAggregations).