docs: def append(
              self,
              moment_or_operation_tree: Union[ops.Moment, ops.OP_TREE],
              strategy: InsertStrategy = InsertStrategy.EARLIEST):
          """Appends operations onto the end of the circuit.
  
          Moments within the operation tree are appended intact.
  
          Args:
              moment_or_operation_tree: The moment or operation tree to append.
              strategy: How to pick/create the moment to put operations into.
          """
          self.insert(len(self._moments), moment_or_operation_tree, strategy)