docs: def get(self, arg):
          """
          Return instance object with given EC2 ID or nametag.
          """
          try:
              reservations = self.get_all_instances(filters={'tag:Name': [arg]})
              instance = reservations[0].instances[0]
          except IndexError:
              try:
                  instance = self.get_all_instances([arg])[0].instances[0]
              except (_ResponseError, IndexError):
                  # TODO: encapsulate actual exception for debugging
                  err = "Can't find any instance with name or ID '%s'" % arg
                  raise ValueError(err)
          return instance