class_docstr: A context manager to change the default tensor type when tensors get created.
  
  See: :func:`torch.set_default_dtype`
code: def __init__(self, dtype: torch.dtype) -> None:
      self._previous_dtype: torch.dtype = torch.get_default_dtype()
      self._new_dtype = dtype
  
file_path: pytorch-lightning/src/lightning/fabric/plugins/precision/utils.py
imports: from typing import Any, Mapping, Type, Union
  import torch
  from torch import Tensor
label_desc: Use image node_id 1 to create a new _DtypeContextManager object  with example: obj = _DtypeContextManager(dtype)