### Question:
ListArgumentSet implements ArgumentSet { @Override public int length() { return arguments.size(); } ListArgumentSet(List<String> arguments); @Override String get(int index); @Override int length(); @Override List<String> getAll(); @Override boolean isEmpty(); @Override boolean has(String argument); @Override String join(); @Override String[] toArray();  }### Answer:
@Test public void length() { assertEquals(4, listArgumentSet.length()); }