import java.util.LinkedHashSet;
 
class Ideone {
	public static void main (String[] args) {
		LinkedHashSet<LinkedHashSet<String>> block = new LinkedHashSet<>();
		LinkedHashSet<String> lineOne = new LinkedHashSet<>();
		lineOne.add("Hello");
		lineOne.add("World");
		block.add(lineOne);
		LinkedHashSet<String> lineTwo = new LinkedHashSet<>();
		lineTwo.add("Hi");
		lineTwo.add("Universe");
		block.add(lineTwo);
 
		block.forEach(line -> {
			line.forEach(System.out::print);
			System.out.println();
		});
	}
}

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