var QuantityObject … var quantityTypeValue … var QuantityType … type Quantity … func (d Quantity) ConvertToNative(typeDesc reflect.Type) (interface{ … } func (d Quantity) ConvertToType(typeVal ref.Type) ref.Val { … } func (d Quantity) Equal(other ref.Val) ref.Val { … } func (d Quantity) Type() ref.Type { … } func (d Quantity) Value() interface{ … }