/// <remarks/>
 public void GetCustomerBillingAsync(GetCustomerBillingRequest GetCustomerBillingRequest, object userState) {
     if ((this.GetCustomerBillingOperationCompleted == null)) {
         this.GetCustomerBillingOperationCompleted = new System.Threading.SendOrPostCallback(this.OnGetCustomerBillingOperationCompleted);
     }
     this.InvokeAsync("GetCustomerBilling", new object[] {
                 GetCustomerBillingRequest}, this.GetCustomerBillingOperationCompleted, userState);
 }
 /// <remarks/>
 public void GetCustomerBillingAsync(GetCustomerBillingRequest GetCustomerBillingRequest) {
     this.GetCustomerBillingAsync(GetCustomerBillingRequest, null);
 }