class_docstr: Extracts and exports image featuers for tensorboard projector during inference
code: def before_fit(self):
      self.run = (
          not hasattr(self.learn, "lr_finder")
          and hasattr(self, "gather_preds")
          and rank_distrib() == 0
      )
      if not self.run:
          return
      self._setup_writer()
  
imports: from __future__ import annotations
  from ..basics import *
  import tensorboard
  from torch.utils.tensorboard import SummaryWriter
  from .fp16 import ModelToHalf
  from .hook import hook_output
  from ..text.all import LMLearner, TextLearner
  from ..vision.data import *
  from ..vision.core import TensorPoint, TensorBBox
label_desc: Use image node_id 2 for calling the TensorBoardProjectorCallback obj's underlying member method code with example usage: obj.before_fit() without return types