code: def __len__(self) -> int:
      return len(self._dataloader)
  
imports: import inspect
  from functools import wraps
  from typing import Any, Callable, Dict, Generator, Iterator, List, Mapping, Optional, TypeVar, Union, overload
  import torch
  from lightning_utilities.core.apply_func import apply_to_collection
  from torch import Tensor
  from torch import nn
  from torch.nn.modules.module import _IncompatibleKeys
  from torch.optim import Optimizer
  from torch.utils.data import DataLoader
  from typing_extensions import override
  from lightning.fabric.plugins import Precision
  from lightning.fabric.strategies import Strategy
  from lightning.fabric.utilities import move_data_to_device
  from lightning.fabric.utilities.data import _set_sampler_epoch
  from lightning.fabric.utilities.device_dtype_mixin import _DeviceDtypeModuleMixin
  from lightning.fabric.utilities.imports import _TORCH_GREATER_EQUAL_2_0
  from lightning.fabric.utilities.types import Optimizable
label_desc: Use image node_id 3 for calling the _FabricDataLoader obj's underlying member method code with example usage: obj.__len__() and returns: len