ansible/test-module produces this result: modify_module() got multiple values for keyword argument 'task_vars'

I used the test-module script to debug modules in ansible but i am getting a strange error:

1 Here is the example i followed:
https://ansible-manual.readthedocs.io/en/stable-2.2/developing_modules.html

So i executed this command

ansible/hacking/test-module -I ansible_python_interpreter=/usr/bin/python -m ./custom_modules/timetest.py

BUT I am getting this error :

[vagrant@db3 vagrant]$ ansible/hacking/test-module -I ansible_python_interpreter=/usr/bin/python -m ./custom_modules/timetest.py
Traceback (most recent call last):
File “ansible/hacking/test-module”, line 270, in
main()
File “ansible/hacking/test-module”, line 251, in main
(modfile, modname, module_style) = boilerplate_module(options.module_path, options.module_args, interpreters, options.check, options.filename)
File “ansible/hacking/test-module”, line 154, in boilerplate_module
task_vars=task_vars
TypeError: modify_module() got multiple values for keyword argument ‘task_vars’

Here is details my ansible

[vagrant@db3 vagrant]$ ansible --version
ansible 2.5.0
config file = /etc/ansible/ansible.cfg
configured module search path = [u’/home/vagrant/.ansible/plugins/modules’, u’/usr/share/ansible/plugins/modules’]
ansible python module location = /usr/lib/python2.7/site-packages/ansible
executable location = /usr/bin/ansible
python version = 2.7.5 (default, Aug 4 2017, 00:39:18) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]

When i checked the modify_module function in module_common.py i see that task_vars is in position 4

def modify_module(module_name, module_path, module_args, task_vars=None, templar=None, module_compression='ZIP_STORED', async_timeout=0, become=False,
                  become_method=None, become_user=None, become_password=None, become_flags=None, environment=None):

but when it is used in the test-module it is not on position 4 but Templar is:

(module_data, module_style, shebang) = module_common.modify_module(
modname,
modfile,
complex_args,
Templar(loader=loader),
task_vars=task_vars
)

Please is this a bug? and if it is, how to make this work?

Regards,
Sessy