docs: def _check_write_command_response(results):
      """Backward compatibility helper for write command error handling.
      """
      errors = [res for res in results
                if "writeErrors" in res[1] or "writeConcernError" in res[1]]
      if errors:
          # If multiple batches had errors
          # raise from the last batch.
          offset, result = errors[-1]
          # Prefer write errors over write concern errors
          write_errors = result.get("writeErrors")
          if write_errors:
              # If the last batch had multiple errors only report
              # the last error to emulate continue_on_error.
              error = write_errors[-1]
              error["index"] += offset
              if error.get("code") == 11000:
                  raise DuplicateKeyError(error.get("errmsg"), 11000, error)
              raise WriteError(error.get("errmsg"), error.get("code"), error)
          else:
              error = result["writeConcernError"]
              if "errInfo" in error and error["errInfo"].get('wtimeout'):
                  # Make sure we raise WTimeoutError
                  raise WTimeoutError(
                      error.get("errmsg"), error.get("code"), error)
              raise WriteConcernError(
                  error.get("errmsg"), error.get("code"), error)