code: def get_subnet_id(self, name):
          
          for subnet_id, subnet_name in self.config['subnets'].iteritems():
              if subnet_name == name:
                  return subnet_id
          return name
docs: Return subnet ID for given ``name``, if it exists.
  
          E.g. with a subnet mapping of ``{'abc123': 'ops', '67fd56': 'prod'}``,
          ``get_subnet_id('ops')`` would return ``'abc123'``. If the map has
          non-unique values, the first matching key will be returned.
  
          If no match is found, the given ``name`` is returned as-is. This works
          well for e.g. normalizing names-or-IDs to just IDs.