let siParam = PayUSIParams(billingAmount: <#T##String#>,
paymentStartDate: <#T##Date#>,
paymentEndDate: <#T##Date#>,
billingCycle: <#T##PayUBillingCycle#>,
billingInterval: <#T##NSNumber#>,
billingLimit: <#T##PayuBillingLimit#>,
billingRule: <#T##PayuBillingRule#>)