SparkInterpreter extends Interpreter { public synchronized SparkContext getSparkContext() { if (sc == null) { sc = createSparkContext(); env = SparkEnv.get(); sparkListener = setupListeners(sc); } return sc; } SparkInterpreter(Properties property);  SparkInterpreter(Properties property, SparkContext sc); synchronized SparkContext getSparkContext(); boolean isSparkContextInitialized(); SQLContext getSQLContext(); DependencyResolver getDependencyResolver(); SparkContext createSparkContext(); static String getSystemDefault(
      String envName,
      String propertyName,
      String defaultValue); @Override void open(); @Override List<String> completion(String buf, int cursor); Object getValue(String name); @Override InterpreterResult interpret(String line, InterpreterContext context); InterpreterResult interpret(String[] lines, InterpreterContext context); InterpreterResult interpretInput(String[] lines); @Override void cancel(InterpreterContext context); @Override int getProgress(InterpreterContext context); @Override void close(); @Override FormType getFormType(); JobProgressListener getJobProgressListener(); @Override Scheduler getScheduler(); ZeppelinContext getZeppelinContext(); SparkVersion getSparkVersion();  }
@Test public void emptyConfigurationVariablesOnlyForNonSparkProperties() { Properties intpProperty = repl.getProperty(); SparkConf sparkConf = repl.getSparkContext().getConf(); for (Object oKey : intpProperty.keySet()) { String key = (String) oKey; String value = (String) intpProperty.get(key); repl.logger.debug(String.format("[%s]: [%s]", key, value)); if (key.startsWith("spark.") && value.isEmpty()) { assertTrue(String.format("configuration starting from 'spark.' should not be empty. [%s]", key), !sparkConf.contains(key) || !sparkConf.get(key).isEmpty()); } } }