Protowrapper is a helper class that monkey patches protobuffer classes to assist validation.

It is best explained with an example:

from protobuffer_pb2 import Address

class Address(Protowrapper):

    def check_ip(self):
        return len(self.ip) == 4 || len(self.ip) == 16

    def check_port(self):
        return self.port > 0 and self.port < 1024

    def init(self):
        self.my_instance_variable = 0

    def print(self):
        print("ip:", self.ip, "port:", self.port)
        print("instance var", self.my_instance_variable)

And voila! Address is now a monkey patched protobuffer with those validation checks, initialization function, and other methods.