### Question:
LowerCaseCharSequence implements ComparableCharSequence { @Override public String toString() { return delegate.toString().toLowerCase(); } LowerCaseCharSequence(final CharSequence delegate); @Override char charAt(final int index); @Override ComparableCharSequence subSequence(final int start, final int end); @Override String toString(); @Override int length(); @Override int compareTo(final CharSequence other); @Override boolean equals(final Object obj); @Override int hashCode();  }### Answer:
@Test public void testThatToStringReturnsTheLowerCaseString() throws Exception { assertEquals("hello world!", new LowerCaseCharSequence("Hello WORLD!").toString()); }