class_docstr: 将PIL图像转为Tensor
class_docstr_tok: ["\u5c06PIL\u56fe\u50cf\u8f6c\u4e3aTensor"]
code: def __call__(self, image, target):
      image = F.to_tensor(image).contiguous()
      return image, target
  
imports: import random
  import torch
  import torchvision.transforms
  from torchvision.transforms import functional
  from src import dboxes300_coco, calc_iou_tensor, Encoder
label_desc: Use image node_id 1 for calling the ToTensor obj's underlying member method code with example usage: obj.__call__(image, target) and returns: image,  target