### Question:
WindowingContact implements WindowingItemWithData, Serializable { public static Builder builder() { return new Builder(); } WindowingContact(int uid, MSContact msContact); static Builder builder(); @Override int getUid(); @Override MSContact getApplicationData(); @Override String toString(); @Override final int hashCode(); @Override final boolean equals(Object object);  }### Answer:
@Test(expected=IllegalArgumentException.class) public void testBuildWithNullId() { WindowingContact.builder() .applicationData(new MSContact()) .build(); }
@Test public void testBuildWithNullMSContact() { WindowingContact.builder() .uid(1) .build(); }