Start the worker process.

def start(self):
        """Start the worker process."""
        error, output = None, None
        try:
            time.sleep(0.1)
            output = self.method(*self.args, **self.kwargs)
        except Exception as err:
            logger.debug(str((self.method.__module__, self.method.__name__,
                              err)))
            error = str(err)
            error = error.replace('(', '')
            error = error.replace(')', '')
#            try:
#                error = err[0]
#            except Exception:
#                try:
#                    error = err.message
#                except Exception as err2:
#                    error = ''

        self.sig_finished.emit(self, output, str(error))
        self._is_finished = True