This is the asynchronous version of System.Data.Common.DbDataReader.NextResult. Providers should override with an appropriate implementation. The cancellationToken may optionally be ignored. The default implementation invokes the synchronous System.Data.Common.DbDataReader.NextResult method and returns a completed task, blocking the calling thread. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by System.Data.Common.DbDataReader.NextResult will be communicated via the returned Task Exception property. Other methods and properties of the DbDataReader object should not be invoked while the returned Task is not yet completed. Advances the reader to the next result when reading the results of a batch of statements.