code: def linkcode_resolve(domain, info):
      
      if domain != 'py':
          return None
      modname = info['module']
      fullname = info['fullname']
      submod = sys.modules.get(modname)
      if submod is None:
          return None
      obj = submod
      for part in fullname.split('.'):
          try:
              obj = getattr(obj, part)
          except:
              return None
      try:
          fn = inspect.getsourcefile(obj)
      except:
          fn = None
      if not fn:
          return None
      try:
          source, lineno = inspect.findsource(obj)
      except:
          lineno = None
      if lineno:
          linespec = "#L%d" % (lineno + 1)
      else:
          linespec = ""
      fn = relpath(fn, start='..')
      return "https://github.com/mithrandi/txacme/blob/%s/%s%s" % (
          txacme_version_info['full-revisionid'], fn, linespec)
docs: Determine the URL corresponding to Python object