new_contents: """Determine the generator format"""
  from collections import ChainMap
  
  DEFAULT_FORMAT = {
      'domain': 'example.com',
      'app': '{repo}{project}',
      'dns_elb': '{repo}.{project}.{env}.{domain}',
      'dns_instance': '{repo}{project}-xx.{env}.{domain}',
      'iam_base': '{project}_{repo}',
      'iam_user': '{project}_{repo}',
      'iam_group': '{project}',
      'iam_role': '{project}_{repo}_role',
      'iam_policy': '{project}_{repo}_policy',
      'iam_profile': '{project}_{repo}_profile',
      's3_bucket': 'archaius-{env}',
      's3_bucket_path': '{project}/{repo}{project}',
      's3_archaius_name': 'archaius-{env}/{project}/{repo}{project}/',
      'jenkins_job_name': '{project}_{repo}',
      'git_repo': '{raw_project}/{raw_repo}',
      'git_repo_qe': '{raw_project}/{raw_repo}-qa',
      'git_repo_configs': '{raw_project}/{raw_repo}-config',
  }
  
  
  class Formats(object):
  
      def __init__(self, config={}):
          self.config = ChainMap(config, DEFAULT_FORMAT)
  
      def get_formats(self):
          return self.config
  
      def __getitem__(self, key):
          return self.config[key]
  
subject: Add Formats