def __init__(self, rev_reg_def: dict, tails: Tails = None):
LOGGER.debug('<STR_LIT>', rev_reg_def, tails)<EOL>self._rev_reg_def = rev_reg_def or None<EOL>self._tails = tails or None<EOL>self._rr_delta_frames = []  <EOL>self._rr_state_frames = []  <EOL>LOGGER.debug('<STR_LIT>')<EOL>
Initialize with revocation registry definition, optional tails file.
Set revocation delta frames lists for rev reg deltas and rev reg states empty.

:param rev_reg_def: revocation registry definition
:param tails: current tails file object