pig/src/main/java/com/twitter/elephantbird/pig/util/PigToThrift.java
private static TBase<?, ?> newTInstance(Class<?> tClass) {
    try {
      return (TBase<?, ?>) tClass.newInstance();
    } catch (Exception e) { // not expected.
      throw new RuntimeException(e);
    }
  }
private static TBase<?, ?> newTInstance(Class<?> tClass) {
    try {
      return (TBase<?, ?>) tClass.newInstance();
    } catch (Exception e) { // not expected.
      throw new RuntimeException(e);
    }
  }
return an instance assuming tClass is a Thrift class