code: def check_fillchar(i):
      try:
          c = chr(i)
          c.encode("utf-8").decode()
          format(P.Decimal(0), c + "<19g")
          return c
      except:
          return None
  
file_path: cpython/Modules/_decimal/tests/formathelper.py
imports: import os, sys, locale, random
  import platform, subprocess
  from test.support.import_helper import import_fresh_module
  from shutil import which
label_desc: Use image node_id 3 for calling a global function with example usage: check_fillchar(i) and returns: c, None