### Question:
SimpleComparableCharSequence implements ComparableCharSequence { @Override public char charAt(final int index) { if (index >= length) { throw new ArrayIndexOutOfBoundsException(index); } return value[start + index]; } SimpleComparableCharSequence(final char[] value);  SimpleComparableCharSequence(final char[] value, final int start, final int length); @Override int length(); @Override char charAt(final int index); @Override ComparableCharSequence subSequence(final int start, final int end); @Override int compareTo(final CharSequence other); @Override int hashCode(); @Override boolean equals(final Object obj); @Override String toString();  }### Answer:
@Test public void testCharAt() throws Exception { SimpleComparableCharSequence seq = new SimpleComparableCharSequence("cde-fgh-".toCharArray(), 0, 8); assertEquals(8, seq.length()); for (int i = 0; i < 8; i++) { assertEquals("cde-fgh-".charAt(i), seq.charAt(i)); } }