### Question:
Leaf { public String toString() { final StringBuilder str = new StringBuilder(); for(byte[] block: dataBlock) { str.append(toHexString(block)); } return(str.toString()); } Leaf(final List<byte[]> dataBlock); List<byte[]> getDataBlock(); String toString();  }### Answer:
@Test public final void testToString() { assertTrue("Leaf equals " + leaf.toString() + " and not " + leafString, leaf.toString().equals(leafString)); }