### Question:
PrefixTrieMap { public void putPrefix(final CharSequence seq, final T value) { this.putPrefix(seq, value, false); } PrefixTrieMap(); void putPrefix(final CharSequence seq, final T value); void putPrefix(final CharSequence seq, final T value, boolean includeExactMatch); Optional<PrefixMatch<T>> getPrefix(final CharSequence seq);  }### Answer:
@Test(expected = IllegalArgumentException.class) public void testPutEmptyString() { new PrefixTrieMap<>().putPrefix("", null); }