package externalid type InvoiceExternalIDs struct { Invoicing string `json:"invoicing,omitempty"` Payment string `json:"payment,omitempty"` } func (i *InvoiceExternalIDs) GetInvoicingOrEmpty() string { if i == nil { return "" } return i.Invoicing } type LineExternalIDs struct { Invoicing string `json:"invoicing,omitempty"` } func (i LineExternalIDs) Equal(other LineExternalIDs) bool { return i.Invoicing == other.Invoicing }