In Mongoose how declare dynamic Schema
===

I a newbie to Mongoose and in the official documentation I don't found anything related to what I need.

How can I declare a child schema that is dynamic?

For example:

    var A = new Schema({
        name        : String,
        subtype     : String,
        description : String});
    
    var B = new Schema({
        name        : String,
        description : String
    });
    
    var C = new Schema({
        name        : String,
        type        : [if(type.value == 'A') then uses Schema-A;
                       if(type.value == 'B') then uses Schema-B;
                      ]
    });

Hope it makes sense.

Thanks in advance.
