Decode identityref with wrong namespace/module

Using YDK-gen and YDK-py (R0.5.5),built and installed a private YANG file with its own namespace to supplement trib-protocol (of type identityref) in openconfig-terminal-device. But YDK-py fails to decode trib-protocol from a NETCONF message such as: 

<terminal-device xmlns="http://openconfig.net/yang/terminal-device">

...

<config>

<index>101020411</index>

<trib-protocol xmlns="http://my.com/yang/my-openconfig-exttypes">PROT_UNASSIGNED</trib-protocol>

</config>

 Looking at YDK implementation, when trying to resolve/decode an identityref, it ignores the namespace (my-openconfig-exttypes) with trib-protocol and uses "open-terminal-device" from its root node instead. This seems to be a bug..

Since the effort is in setting up a device that gives the right response.

The yang file is simple and it looks like below. 

module my-openconfig-exttypes {

  yang-version "1";

  namespace "http://my.com/yang/my-openconfig-exttypes";

  prefix "my-oc-exttypes"; 

  import openconfig-transport-types { prefix oc-opt-types; } 

  organization "My"; 

  contact "My Optical Networks"; 

  description "For debug/testing only"; 

  identity PROT_UNASSIGNED {

    base oc-opt-types:TRIBUTARY_PROTOCOL_TYPE;

    description "No protocol specified";

  }

}

The script basically does this:

term = TerminalDevice()

devices = crud.read(provider, term, only_config=True)

 It will be easier if you find an existing device that does something similar with identityref.

 We have some example scripts, which do the similar thing as your yang model, which have been tested and known to work without problems. See this one for example. Corresponding yang file is here.

•  It tries to extract members from encoded XML using their namespace according to their modules/Yang. But this does not work for member of identityref (think of it as a typed "pointer") that may not assume its defined namespace (i.e., "base" type). From the example in my original question:
•      <trib-protocol xmlns="http://my.com/yang/my-openconfig-exttypes">PROT_UNASSIGNED</trib-protocol> 
•  As shown, this instance of trib-protocol is an identityref of a "derived" namespace (not defined in the module/Yang). In current YDK (0.5.5) implementation, this encoded trib-protocol will be ignored since its tag name does not meet the search criteria.