docs: async def issuer_merge_revocation_registry_deltas(rev_reg_delta_json: str,
                                                    other_rev_reg_delta_json: str) -> str:
      """
      Merge two revocation registry deltas (returned by issuer_create_credential or issuer_revoke_credential) to accumulate common delta.
      Send common delta to ledger to reduce the load.
  
      :param rev_reg_delta_json: revocation registry delta json
      :param other_rev_reg_delta_json: revocation registry delta for which PrevAccum value  is equal to current accum value of rev_reg_delta_json.
      :return: Merged revocation registry delta
      """
  
      logger = logging.getLogger(__name__)
      logger.debug(
          "issuer_merge_revocation_registry_deltas: >>> rev_reg_delta_json: %r, other_rev_reg_delta_json: %r",
          rev_reg_delta_json,
          other_rev_reg_delta_json)
  
      if not hasattr(issuer_merge_revocation_registry_deltas, "cb"):
          logger.debug("issuer_merge_revocation_registry_deltas: Creating callback")
          issuer_merge_revocation_registry_deltas.cb = create_cb(CFUNCTYPE(None, c_int32, c_int32, c_char_p))
  
      c_rev_reg_delta_json = c_char_p(rev_reg_delta_json.encode('utf-8'))
      c_other_rev_reg_delta_json = c_char_p(other_rev_reg_delta_json.encode('utf-8'))
  
      merged_revoc_reg_delta_json = await do_call('indy_issuer_merge_revocation_registry_deltas',
                                                  c_rev_reg_delta_json,
                                                  c_other_rev_reg_delta_json,
                                                  issuer_merge_revocation_registry_deltas.cb)
      res = merged_revoc_reg_delta_json.decode()
      logger.debug("issuer_merge_revocation_registry_deltas: <<< res: %r", res)
      return res