/** The EchoDF Class is an example wrapper function that uses the Aster-Spark * API and simply returns the input DataFrame as output. It mimics the behavior of * an echo function and it derives from the base class AsterSparkFunctionDF * which hides all the interactions with Aster. * The Echo class overrides the run method and implements the echo * functionality. * */ class EchoDF (args : Array[String], name: String, mstr:String = null ) extends AsterSparkFunctionDF (args, name, mstr) { /** * The run method is overridden to implement the echo functionality. * @param input The input data frame that reads data from the source. * @param sparkFuncParams String representing the parameters specific to the * function the user is implementing. In this example sparkFuncParams * parameter is not used. * @return The result is a data frame containing all the input data. */ override def run(input:DataFrame, sparkFunctParams: String ): DataFrame = { input } }