using os_user_role module to assign admin role to group in specific domain in multidomain env

[bhreddy]

---
- hosts: localhost
  gather_facts: no
  any_errors_fatal: yes
  tasks:
    - name: Assign admin role to test_group
      os_user_role:
        auth_type: password
        auth:
          auth_url: "https://openstack.api.endpoint.url:5000/v3"
          username: admin
          password: "{{ admin_password }}"
          project_name: admin
          project_domain_name: default
          user_domain_name: default
        domain: ldap_domain
        group: test_group
        role: admin
        project: admin

In multi domain environment, I am trying to assign admin role to group named as 'test_group' in a domain ldap_domain. I am getting exception as "project admin is not valid"