public Object runScript(String src) throws PropertyException {
    try {
      JexlScript script = JEXL.createScript(src);
      ObjectContext<PropertyManager> context = new ObjectContext<>(JEXL, this);
      return script.execute(context);
    } catch(JexlException je) {
      throw new PropertyException("script failed", je);
    }
  }
@Test
  public void testSerDerScript() {
    runSerDer(() -> {
      return (boolean) manager.runScript(
          "setProperty('framework', 'llap');" +
              "setProperty('ser.store', 'Parquet');" +
              "setProperty('ser.der.id', 42);" +
              "setProperty('ser.der.name', 'serder');" +
              "setProperty('ser.der.project', 'Metastore');" +
              "true;");
    });
  }