@Override
	public void afterPropertiesSet() throws Exception {
		Assert.notNull(lineAggregator, "A LineAggregator must be provided.");
	}
Public setter for the {@link LineAggregator}. This will be used to translate the item into a line for output.

@param lineAggregator the {@link LineAggregator} to set
spring-xd-hadoop/src/main/java/org/springframework/xd/batch/item/hadoop/SimpleHdfsTextItemWriter.java