### Question:
LineNeedle extends MeterNeedle implements Cloneable, Serializable { @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof LineNeedle)) { return false; } return super.equals(obj); }  @Override boolean equals(Object obj); @Override int hashCode(); @Override Object clone();  }### Answer:
@Test public void testEquals() { LineNeedle n1 = new LineNeedle(); LineNeedle n2 = new LineNeedle(); assertEquals(n1, n2); assertEquals(n2, n1); }