Return details about the fake process.

def _process_info(self):
        """Return details about the fake process."""
        if not self._process:
            return []

        output, error = self._process.communicate(timeout=5)
        if error is None:
            error = b""
        output = output.decode("utf-8").strip()
        error = error.decode("utf-8").strip()
        info = (u"returncode: %r\n"
                u"output:\n%s\n"
                u"error:\n%s\n" % (self._process.returncode, output, error))
        return [info.encode("utf-8")]