Resample the series based on a provided collection of keys. The values of the series are aggregated into chunks based on the specified keys. Depending on `direction`, the specified key is either used as the smallest or as the greatest key of the chunk (with the exception of boundaries that are added to the first/last chunk). The chunks are then returned as a nested series. ## Parameters - `keys` - A collection of keys to be used for resampling of the series - `direction` - If this parameter is `Direction.Forward`, then each key is used as the smallest key in a chunk; for `Direction.Backward`, the keys are used as the greatest keys in a chunk. ## Remarks This operation is only supported on ordered series. The method throws `InvalidOperationException` when the series is not ordered. [category:Resampling]

public Series<K, Series<K, V>> Resample(
	IEnumerable<K> keys,
	Direction direction
)