Args:
        filename: Where to write tf.records
        tf_examples: An iterable of tf.Example
        serialize: whether to serialize the examples.

def write_tf_examples(filename, tf_examples, serialize=True):
    """
    Args:
        filename: Where to write tf.records
        tf_examples: An iterable of tf.Example
        serialize: whether to serialize the examples.
    """
    with tf.python_io.TFRecordWriter(
            filename, options=TF_RECORD_CONFIG) as writer:
        for ex in tf_examples:
            if serialize:
                writer.write(ex.SerializeToString())
            else:
                writer.write(ex)