@Test
public void test4(){

	transactions.stream()
			.map((t) -> t.getTrader().getName())
			.sorted()
			.forEach(System.out::println);
	System.out.println("------------------------------------");
	String str = transactions.stream()
			.map((t) -> t.getTrader().getName())
			.sorted()
			.reduce("", String::concat);
	System.out.println(str);
	System.out.println("------------------------------------");
	transactions.stream()
			.map((t) -> t.getTrader().getName())
			.flatMap(TestTransaction::filterCharacter)
			.sorted((s1, s2) -> s1.compareToIgnoreCase(s2))
			.forEach(System.out::print);
}