code: def _is_numpy(img):
      return isinstance(img, np.ndarray)
  
file_path: vissl/vissl/data/ssl_transforms/img_pil_to_tensor.py
imports: import numpy
  import torch
  from classy_vision.dataset.transforms import register_transform
  from classy_vision.dataset.transforms.classy_transform import ClassyTransform
  from PIL import Image
label_desc: Use image node_id 1 for calling a global function with example usage: _is_numpy(img) and returns: isinstance