Marshmallow library extension that allows schema (de)multiplexing
This library adds a special kind of schema that actually multiplexes other schemas based on object type. When serializing values, it uses getobjtype() method to get object type name. Then it uses type_schemas name-to-Schema mapping to get schema for that particular object type, serializes object using that schema and adds an extra field with name of object type. Deserialization is reverse.
