public void removeAll() {
    lastKey = null;
    firstKey = null;
    rows.clear();
  }
@Test
  public void testRemoveAll() {
    Table table = new Table(TWO_COLUMN_TABLE);
    assertFalse(table.removeAt(ROW_1));
    table.put(1, ROW_1);
    table.put(2, ROW_2);
    table.put(3, ROW_3);
    table.removeAll();
    assertEquals(0, table.count());
  }