3.16Another realistic conditional Salesforce mapping

{
    External_Customer_ID__c: payload.customerId,
    Name: payload.companyName,

    (Phone: payload.phone)
        if (payload.phone != null),

    (Website: payload.website)
        if (payload.website != null),

    (BillingCity: payload.billing.city)
        if (payload.billing.city != null)
}

This prevents accidental Salesforce field clearing.