def set_default
      set_app_name('RubySpark')
      set_master('local[*]')
      set('spark.ruby.driver_home', Spark.home)
      set('spark.ruby.serializer', default_serializer)
      set('spark.ruby.serializer.compress', default_serializer_compress)
      set('spark.ruby.serializer.batch_size', default_serializer_batch_size)
      set('spark.ruby.executor.command', default_executor_command)
      set('spark.ruby.executor.options', default_executor_options)
      set('spark.ruby.worker.type', default_worker_type)
      load_executor_envs
      # set('spark.ruby.executor.install', default_executor_install)
    end
def set_default
      set_app_name('RubySpark')
      set_master('local[*]')
      set('spark.ruby.driver_home', Spark.home)
      set('spark.ruby.serializer', default_serializer)
      set('spark.ruby.serializer.compress', default_serializer_compress)
      set('spark.ruby.serializer.batch_size', default_serializer_batch_size)
      set('spark.ruby.executor.command', default_executor_command)
      set('spark.ruby.executor.options', default_executor_options)
      set('spark.ruby.worker.type', default_worker_type)
      load_executor_envs
      # set('spark.ruby.executor.install', default_executor_install)
    end
=============================================================================
 Defaults