function test (frequency: PaymentFrequency, inputAmount: number, expectedAmount: number) {
   const actualAmount: number = MonthlyAmountViewFilter.render({
     frequency: frequency,
     amount: inputAmount
   })
   const roundedAmount: number = +actualAmount.toFixed(2)
   expect(roundedAmount).to.equal(expectedAmount)
 }
 expect(() => MonthlyAmountViewFilter.render(null)).to.throw(errorMessage)
 expect(() => MonthlyAmountViewFilter.render({
   frequency: PaymentFrequency.FOUR_WEEKS,
   amount: 0
 })).to.throw(errorMessage)
 expect(() => MonthlyAmountViewFilter.render({
   frequency: undefined,
   amount: 100
 })).to.throw(errorMessage)
 expect(() => MonthlyAmountViewFilter.render({
   frequency: PaymentFrequency.MONTH,
   amount: undefined
 })).to.throw(errorMessage)
 expect(() => MonthlyAmountViewFilter.render(undefined)).to.throw(errorMessage)