newstr object instead of str object python2.7

When I am using `param` to get a string inside proxy object, I can't directly receive a str object, I am receiving an object with type.
My proxy object:
```
from iotile.core.hw.proxy.proxy import TileBusProxyObject
from iotile.core.utilities.typedargs.annotate import context, param

@context("DemoProxy1")
class DemoProxyObject(TileBusProxyObject):

@classmethod
def ModuleName(cls):
return 'Demo01'

@param("test_var", "str")
def get_test_rpc_v1(self, test_var):
print(type(test_var))

```
Steps to reproduce:
1. Run get_test_rpc_v1