The mixin exposes a
meta property with the following properties:
collection- (Optional) A collection the model belongs to
id- The model id
type- The model type
original- (Optional) The original model if the model is a clone
refs- An object with reference ids. The keys are reference names, while the values can be either ids or array of ids (depending on the reference type).
snapshot- An immutable snapshot of the model at this exact moment