### Question:
ComplexNumber { public ComplexNumber div(double d) { return mul(1.0 / d); } ComplexNumber(double real, double imaginary); static ComplexNumber fromReal(double real); static ComplexNumber fromImaginary(double imaginary); static ComplexNumber fromMagnitudeAndAngle(double magnitude, double angle); static ComplexNumber parse(String s); double getReal(); double getImaginary(); double getMagnitude(); double getAngle(); ComplexNumber conjugate(); ComplexNumber add(ComplexNumber c); ComplexNumber sub(ComplexNumber c); ComplexNumber mul(double d); ComplexNumber mul(ComplexNumber c); ComplexNumber div(double d); ComplexNumber div(ComplexNumber c); ComplexNumber power(int n); ComplexNumber[] root(int n); @Override int hashCode(); @Override boolean equals(Object obj); @Override String toString(); static final ComplexNumber ONE; static final ComplexNumber MINUS_ONE; static final ComplexNumber ZERO; static final ComplexNumber I; static final ComplexNumber MINUS_I; static final double THRESHOLD; }### Answer:
@Test void testDivWithOne() { for (int index = 0; index < numbers.length; index++) { assertEquals(numbers[index], numbers[index].div(ComplexNumber.ONE)); } }