<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def _find_joliet_record(self, joliet_path):
        # type: (bytes) -> dr.DirectoryRecord
        '''
        An internal method to find an directory record on the ISO given a Joliet
        path.  If the entry is found, it returns the directory record object
        corresponding to that entry.  If the entry could not be found, a
        pycdlibexception.PyCdlibInvalidInput is raised.

        Parameters:
         joliet_path - The Joliet path to lookup.
        Returns:
         The directory record entry representing the entry on the ISO.
        '''
        if self.joliet_vd is None:
            raise pycdlibexception.PyCdlibInternalError('Joliet path requested on non-Joliet ISO')
        return _find_dr_record_by_name(self.joliet_vd, joliet_path, 'utf-16_be')