** Marks a type to be mapped as a top level document in a MongoDB collection.
@FacetMeta { inherited = true }
facet class Entity {
    ** Name of the MongoDB collection that documents are stored under. 
    ** Defaults to the type name.
    const Str? name

** Marks a field as a property of a MongoDB document.
facet class Property {

    ** Name of the MongoDB object key this field maps to. 
    ** Defaults to the field name.
    const Str?  name

    ** The implementation 'Type' to be instantiated should this field reference a mixin or a superclass. 
    ** Used when mapping from MongoDB documents to Fantom objects. 
    ** Defaults to the field type.
    const Type? implType