code: def _warn_if_deprecated(key):
      
  
      d = _get_deprecated_option(key)
      if d:
          if d.msg:
              print(d.msg)
              warnings.warn(d.msg, DeprecationWarning)
          else:
              msg = "'%s' is deprecated" % key
              if d.removal_ver:
                  msg += ' and will be removed in %s' % d.removal_ver
              if d.rkey:
                  msg += ", please use '%s' instead." % d.rkey
              else:
                  msg += ', please refrain from using it.'
  
              warnings.warn(msg, DeprecationWarning)
          return True
      return False
docs: Checks if `key` is a deprecated option and if so, prints a warning.
      Returns
      -------
      bool - True if `key` is deprecated, False otherwise.