code: def is_link(s):
      return s is not None and s.startswith("http")
  
file_path: PaddleOCR/ppocr/utils/network.py
imports: import os
  import sys
  import tarfile
  import requests
  from tqdm import tqdm
  from ppocr.utils.logging import get_logger
label_desc: Use image node_id 4 for calling a global function with example usage: is_link(s) and returns: unknown