@Test
public void testHashCode() {

  StringContainer c1 = new StringContainer(",");
  c1.addHead("a", "b", "c123");
  c1.addTail("a", "12", "c");
  c1.addTail("1284736", "b", "c");
  StringContainer c2 = new StringContainer(TsFileConstant.PATH_SEPARATOR);
  c2.addHead("a", "b", "c123");
  c2.addTail("a", "12", "c");
  c2.addTail("1284736", "b", "c");
  StringContainer copyC = c1.clone();
  assertEquals(c1.hashCode(), copyC.hashCode());
  assertNotEquals(c1.hashCode(), c2.hashCode());
  StringContainer c3 = new StringContainer(",");
  c3.addHead("a", "b", "c123");
  assertNotEquals(c1.hashCode(), c3.hashCode());
  StringContainer c4 = new StringContainer(",");
  c4.addTail("a", "b", "c123");
  assertNotEquals(c1.hashCode(), c4.hashCode());
}