### Question:
BillFormat implements Serializable { @Override public int hashCode() { return Objects.hash(outputSize, language, separatorType, fontFamily, graphicsFormat); } BillFormat();  BillFormat(BillFormat format); OutputSize getOutputSize(); void setOutputSize(OutputSize outputSize); Language getLanguage(); void setLanguage(Language language); SeparatorType getSeparatorType(); void setSeparatorType(SeparatorType separatorType); String getFontFamily(); void setFontFamily(String fontFamily); GraphicsFormat getGraphicsFormat(); void setGraphicsFormat(GraphicsFormat graphicsFormat); int getResolution(); void setResolution(int resolution); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString();  }### Answer:
@Test void hashCodeTest() { BillFormat format1 = new BillFormat(); BillFormat format2 = new BillFormat(); assertEquals(format1.hashCode(), format2.hashCode()); }