'Get inventory folder for organizing volume backings.
The inventory folder for organizing volume backings has the following
hierarchy:
<Datacenter_vmFolder>/OpenStack/Project (<project_id>)/
<volume_folder>
where volume_folder is the vmdk driver config option
"vmware_volume_folder".
:param datacenter: Reference to the datacenter
:param project_id: OpenStack project ID
:return: Reference to the inventory folder'

def _get_volume_group_folder(self, datacenter, project_id):

    volume_folder_name = self.configuration.vmware_volume_folder
    project_folder_name = ('Project    (%s)' % project_id)
    folder_names = ['OpenStack', project_folder_name, volume_folder_name]
    return self.volumeops.create_vm_inventory_folder(datacenter, folder_names)
