comment

externals/kyuubi-spark-sql-engine/src/test/scala/org/apache/spark/kyuubi/benchmark/Benchmark.scala

@@ -27,6 +27,28 @@ import scala.util.Try
 import org.apache.commons.io.output.TeeOutputStream
 import org.apache.commons.lang3.SystemUtils
 import org.apache.spark.util.Utils
+
+/**
+ * Copied from Apache Spark
+ * [[org.apache.spark.benchmark.Benchmark]] of the spark-core module
+ *
+ * Utility class to benchmark components. An example of how to use this is:
+ *  val benchmark = new Benchmark("My Benchmark", valuesPerIteration)
+ *   benchmark.addCase("V1")(<function>)
+ *   benchmark.addCase("V2")(<function>)
+ *   benchmark.run
+ * This will output the average time to run each function and the rate of each function.
+ *
+ * The benchmark function takes one argument that is the iteration that's being run.
+ *
+ * @param name name of this benchmark.
+ * @param valuesPerIteration number of values used in the test case, used to compute rows/s.
+ * @param minNumIters the min number of iterations that will be run per case, not counting warm-up.
+ * @param warmupTime amount of time to spend running dummy case iterations for JIT warm-up.
+ * @param minTime further iterations will be run for each case until this time is used up.
+ * @param outputPerIteration if true, the timing for each run will be printed to stdout.
+ * @param output optional output stream to write benchmark results to
+ */
 class Benchmark(
     name: String,
     valuesPerIteration: Long,