code: def exists(x):
      return x is not None
  
file_path: ColossalAI/examples/images/diffusion/ldm/util.py
imports: import importlib
  from inspect import isfunction
  import numpy
  import torch
  from PIL import Image, ImageDraw, ImageFont
  from torch import optim
label_desc: Use image node_id 4 for calling a global function with example usage: exists(x) and returns: unknown