How to change two node groups to have identical input identifiers?

I want to be able to switch between Node Groups without losing input/output connections.

It seems for this to work Node Group input identifiers need to be equal:
a3087d

>>> bpy.data.node_groups["NodeGroup"].outputs[0].identifier="test"
AttributeError:
bpy_struct: attribute "identifier" from "NodeSocketInterfaceShader" is read-only

I tried find GUI way to change identifiers, but there doesn’t seem to be any.