function setTotalSharesOfAccountInternal(address account) internal pausable {
  require(
    isVcaRegistered[account] == false || hasRole(MIGRATOR_ROLE, msg.sender),
    "STAKING: Account already registered."
  );

  uint256 totalShares;
  //pull the layer 2 staking sessions for the account
  uint256[] storage sessionsOfAccount = sessionsOf[account];

  for (uint256 i = 0; i < sessionsOfAccount.length; i++) {
    if (sessionDataOf[account][sessionsOfAccount[i]].withdrawn)
      //make sure the stake is active; not withdrawn
      continue;

    totalShares = totalShares.add( //sum total shares
      sessionDataOf[account][sessionsOfAccount[i]].shares
    );
  }

  //pull stakes from layer 1
  uint256[] memory v1SessionsOfAccount = stakingV1.sessionsOf_(account);

  for (uint256 i = 0; i < v1SessionsOfAccount.length; i++) {
    if (sessionDataOf[account][v1SessionsOfAccount[i]].shares != 0)
      //make sure the stake was not withdran.
      continue;

    if (v1SessionsOfAccount[i] > lastSessionIdV1) continue; //make sure we only take layer 1 stakes in consideration

    (
      uint256 amount,
      uint256 start,
      uint256 end,
      uint256 shares,
      uint256 firstPayout
    ) = stakingV1.sessionDataOf(account, v1SessionsOfAccount[i]);

    (amount);
    (start);
    (end);
    (firstPayout);

    if (shares == 0) continue;

    totalShares = totalShares.add(shares); //calclate total shares
  }

  isVcaRegistered[account] = true; //confirm the registration was completed

  if (totalShares != 0) {
    totalSharesOf[account] = totalShares;
    totalVcaRegisteredShares = totalVcaRegisteredShares.add(totalShares); //update the global total number of VCA registered shares

    //init deductBalances with the present values
    for (uint256 i = 0; i < divTokens.length(); i++) {
      deductBalances[account][divTokens.at(i)] = totalShares.mul(
        tokenPricePerShare[divTokens.at(i)]
      );
    }
  }

  emit AccountRegistered(account, totalShares);
}