code: def _mask_to_box(mask):
      pos_indices = np.where(mask)
      x1 = np.min(pos_indices[1])
      x2 = np.max(pos_indices[1])
      y1 = np.min(pos_indices[0])
      y2 = np.max(pos_indices[0])
      return [x1, y1, x2, y2]
  
imports: import numpy
  import eta.core.utils
  import fiftyone.core.labels
  import fiftyone.core.utils
  import fiftyone.utils.torch
  import fiftyone.zoo.models
  import torch
label_desc: Use image node_id 4 for calling a global function with example usage: _mask_to_box(mask) and returns: list