### Question:
HistogramBin implements Cloneable, Serializable { @Override public boolean equals(Object obj) { if (obj == null) { return false; } if (obj == this) { return true; } if (obj instanceof HistogramBin) { HistogramBin bin = (HistogramBin) obj; boolean b0 = bin.startBoundary == this.startBoundary; boolean b1 = bin.endBoundary == this.endBoundary; boolean b2 = bin.count == this.count; return b0 && b1 && b2; } return false; } HistogramBin(double startBoundary, double endBoundary); int getCount(); void incrementCount(); double getStartBoundary(); double getEndBoundary(); double getBinWidth(); @Override boolean equals(Object obj); @Override Object clone();  }### Answer:
@Test public void testEquals() { double start = 10.0; double end = 20.0; HistogramBin b1 = new HistogramBin(start, end); HistogramBin b2 = new HistogramBin(start, end); assertEquals(b1, b2); assertEquals(b2, b1); }