--module-path target/lib \
--add-modules=javafx.controls,javafx.base,javafx.graphics,commons.configuration,commons.csv,org.apache.logging.log4jList<String> x = Arrays.asList(new String[] { "a", "b" });
System.err.println("x: " + x);
List<String> y = x.stream().map(o -> {
List<String> v = new ArrayList<String>();
v.add(o);
v.add(o);
return v;
}).flatMap(Collection::stream).collect(Collectors.toList());
System.err.println("y: " + y);x: [a, b]
y: [a, a, b, b]
localhost, 14000очевидно