### Question:
MonetaryOperators { public static MonetaryOperator reciprocal() { return RECIPROCAL; } private  MonetaryOperators(); static MonetaryOperator reciprocal(); static MonetaryOperator permil(BigDecimal decimal); static MonetaryOperator permil(Number number); static MonetaryOperator permil(Number number, MathContext mathContext); static MonetaryOperator percent(BigDecimal decimal); static MonetaryOperator percent(Number number); static MonetaryOperator minorPart(); static MonetaryOperator majorPart(); static MonetaryOperator rounding(); static MonetaryOperator rounding(RoundingMode roundingMode); static MonetaryOperator rounding(RoundingMode roundingMode, int scale); static MonetaryOperator rounding(int scale);  }### Answer:
@Test public void testReciprocal() { MonetaryAmount m = Monetary.getDefaultAmountFactory() .setCurrency("CHF").setNumber(200).create(); MonetaryAmount r = m.with(MonetaryOperators.reciprocal()); assertEquals( Monetary.getDefaultAmountFactory().setCurrency("CHF") .setNumber(BigDecimal.ONE.divide(BigDecimal.valueOf(200))) .create(), r); }
@Test(expectedExceptions = NullPointerException.class) public void testReciprocal_Null() { MonetaryOperators.reciprocal().apply(null); }