### Question:
Date implements Comparable<Date> { public static Date valueOf(StringOption dateString, Date.Format format) { if (dateString == null) { throw new IllegalArgumentException("dateString must not be null"); } if (format == null) { throw new IllegalArgumentException("format must not be null"); } if (dateString.isNull()) { return null; } return valueOf(dateString.getAsString(), format); } Date();  Date(int year, int month, int day);  Date(int elapsedDays); int getElapsedDays(); void setElapsedDays(int elapsed); int getYear(); int getMonth(); int getDay(); @Override int hashCode(); @Override boolean equals(Object obj); @Override int compareTo(Date o); @Override String toString(); static Date valueOf(StringOption dateString, Date.Format format); static Date valueOf(String dateString, Date.Format format); static final String FORMAT; }### Answer:
@Test public void parse_null() { StringOption option = new StringOption(null); Date date = Date.valueOf(option, Date.Format.SIMPLE); assertThat(date, is(nullValue())); }