copyWith method
Implementation
PSLFStatus copyWith(
    {DateTime? estimatedEligibilityDate,
    double? paymentsMade,
    double? paymentsRemaining}) {
  return PSLFStatus(
      estimatedEligibilityDate:
          estimatedEligibilityDate ?? this.estimatedEligibilityDate,
      paymentsMade: paymentsMade ?? this.paymentsMade,
      paymentsRemaining: paymentsRemaining ?? this.paymentsRemaining);
}