'Return a folder hierarchy containing Data Managers.'

def build_data_managers_folder(self, folder_id, data_managers, label=None):

    if data_managers:
        if (label is None):
            label = 'Data    Managers'
        data_manager_id = 0
        folder_id += 1
        data_managers_root_folder = Folder(id=folder_id, key='root', label='root', parent=None)
        folder_id += 1
        key = 'valid_data_managers'
        folder = Folder(id=folder_id, key=key, label=label, parent=data_managers_root_folder)
        data_managers_root_folder.folders.append(folder)
        data_manager_id += 1
        data_manager = DataManager(id=data_manager_id, name='Name', version='Version', data_tables='Data    Tables')
        folder.valid_data_managers.append(data_manager)
        for data_manager_dict in data_managers.values():
            data_manager_id += 1
            try:
                name = data_manager_dict.get('name', '')
                version = data_manager_dict.get('version', '')
                data_tables = ',    '.join(data_manager_dict.get('data_tables', ''))
            except Exception as e:
                name = str(e)
                version = 'unknown'
                data_tables = 'unknown'
            data_manager = DataManager(id=data_manager_id, name=name, version=version, data_tables=data_tables)
            folder.valid_data_managers.append(data_manager)
    else:
        data_managers_root_folder = None
    return (folder_id, data_managers_root_folder)
