public HdfsSink fileName(String fileName) {
		Assert.hasText(fileName, "FileName must not be empty nor null.");
		this.fileName = fileName;
		return this;
	}
Sets the file Name that the hdfs sink will write the data.
@param fileName the name of the file
@return the current HdfsSink instance.
spring-xd-test-fixtures/src/main/java/org/springframework/xd/test/fixtures/HdfsSink.java