Do not include the code of the external libraries (i.e., vnf template and nffg library); include them in your project as submodules in order to avoid code duplication.
@farmanullahcs : the link to vnf_template_library submodule looks pretty old. Can you update it with a newer version and make sure that everything still works?
Do not include the code of the external libraries (i.e., vnf template and nffg library); include them in your project as submodules in order to avoid code duplication.