### Question:
ProgramArguments { public int size() { return programArguments.size(); } ProgramArguments();  ProgramArguments(ProgramArguments source); void addAll(Map<String, String> arguments); void add(String name, String value); int size(); String get(int index); String[] toArray(); boolean isEmpty(); void addFilename(String filename); String getFilename(); @Override String toString();  }### Answer:
@Test public void creatingACopyOfANullInstanceCreatesAnEmptyInstance() { ProgramArguments copy = new ProgramArguments(null); assertThat(copy.size(), is(0)); }