Models specifying omitempty

[klische]

I noticed that MX models are specified with omitempty. This results in outputting models/JSON that don't contain objects that have null values, and can cause broken schema generation. For example, on Apple's Swift Codables, decoding JSON will throw an exception if the schema changes from what was expected.

Was there a reason to have omitempty specified? Is there any danger to removing omitempty? I'm also happy to create a PR if you think that omitempty can be safely removed across all models.

[klische]

I apologize for not providing an example:

type Account struct {
	Apr               float32 `json:"apr,omitempty"`
	Apy               float32 `json:"apy,omitempty"`
	AvailableBalance  float32 `json:"available_balance,omitempty"`
	AvailableCredit   float32 `json:"available_credit,omitempty"`
	Balance           float32 `json:"balance,omitempty"`

[while-loop]

I think the omitempty is needed since some models are used for both requests and responses.

POSTing to create user with an empty "" guid string will return a 400 that GUID is an unpermitted param.