docs: def _connection_defaults(user=None, host=None, port=None, maintenance_db=None):
      '''
      Returns a tuple of (user, host, port, db) with config, pillar, or default
      values assigned to missing values.
      '''
      if not user:
          user = __salt__['config.option']('postgres.user')
      if not host:
          host = __salt__['config.option']('postgres.host')
      if not port:
          port = __salt__['config.option']('postgres.port')
      if not maintenance_db:
          maintenance_db = __salt__['config.option']('postgres.maintenance_db')
  
      return (user, host, port, maintenance_db)