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