### Question:
Range { public static <T extends Comparable<? super T>> Range<T> fixed(final T fixed) { if (fixed == null) { throw new IllegalArgumentException("fixed bound cannot be null"); } return closed(fixed, fixed); } protected  Range(final T lowerBound, final T upperBound); Range<T> limit(final Range<T> limit); T lowerBound(); T upperBound(); @Override int hashCode(); @Override boolean equals(final Object o); static Range<T> closed(final T lowerBound, final T upperBound); static Range<T> fixed(final T fixed);  }### Answer:
@Test(expected = IllegalArgumentException.class) public void fixedBoundCannotBeNull() { fixed((Comparable) null); }